It could get a bit preachy, honestly.
Back then writing on popular network TV shows could get away with beating the viewer over the head with a lesson/moral explicitly explained by a character with delivery about as subtle as an after school special. So a lofty Picard speech or whatever wouldn't stand out much from whatever else you'd see that night.
DS9 is still pretty earnest but you can start to see the evolution of writing/viewer taste as you get closer to the 2000s (also the freedom to follow the formulaic episodic structure of network TV a bit less rigidly).
The problem with TNG wasn't so much the preachiness, which is still normal for TV. It's that the moral system behind it was actually quite poor. Picard's character was certainly not the paragon this thread is making him out to be - the more you look at Star Trek the worse it morally gets. It's one of those shows that works best when you don't think about the worldbuilding too much. And the Picard character only seems moral and superior on the surface because of the way Stewart acted him, and because his character is so unemotional, not because of what he actually does.
Consider the moral lessons of TNG and Picard.
Picard isn't married, has no family or children, and apparently no desire to change that. He's actually distinctly uncomfortable around children. Instead he married his job, which is all consuming. Right there that renders the character boring, overly intense and unrelatable for many people. When he gets assimilated by the Borg there's no emotional impact because it's not clear who cares about Picard being turned into an alien except his staff, whose only concern is professional duty. In fact when Riker decides to attack the cube with Picard still on board, he barely hesitates, and why would he? Picard keeps everyone around him at great emotional distance at all times. When the writers want to show Picard having an emotional breakdown about his traumatic experience, they have to show him running home to a brother he hardly ever sees or talks to, because that's the only character the writers have who might care about Picard as a person. Sad.
Picard is supposedly a culture maven, but neither him nor his crew ever creates any. They're obsessed with replaying stories and music old even when the show was made like Moby Dick, Beethoven, Shakespeare, detective stories set in the 1940s.
Although the Enterprise has many crappy jobs on it along with many scarce resources (e.g. holodeck time), crew are unpaid. Picard says everyone on the Enterprise is there because Starfleet is prestigious and he seems fine with that idea. This arrangement could never work in reality so he comes across as delusional, and worse, we are left to assume there actually are mechanisms that incentivize or force people to beam down into severe danger, but Picard pretends they don't exist.
By the 1980s Roddenberry was a Maoist and the Federation appears to be some sort of communist dictatorship. We're told it's abolished money and we don't encounter operating businesses or conventional democratic politics. There is notionally some sort of elected leader in the Federation but they don't seem to control anything and Starfleet does whatever it wants. For example, TNG doesn't show Picard being given new orders because the elected government was changed, nor does Picard ever wonder how his actions might affect politics back home.
Picard holds the capitalist Ferengi in contempt and makes dumb diplomatic mistakes, like referring to "civilized societies" when talking to a Ferengi captain despite that the Ferengi fly around in advanced spaceships. This is because Picard views trade as dirty and beneath him.
Although he does occasionally disagree with Starfleet orders, he slavishly follows the Prime Directive even when the outcome would be absurd, like the entire civilization dying. He never even questions this rule despite the writers realizing that it leads to immoral outcomes! Starfleet is ambiguously presented as sometimes a sort of scientific research org and other times a military that in DS9 implements full blown martial law, suggesting the normal military/civilian separation doesn't exist. Picard never questions the structure of Starfleet or Federation society, which he seems to view as automatically superior (Sisko does a lot better in this regard).
Their second attempt at this created the Borg though, so they did get it very right in the end!
How does it show this? May be just your bias.
Star Trek was always like this.
Honestly, I think the main reason they were hard to sell as the series villains wasn't the capitalist part, it was the fact that they were scrawny and unintimidating. They were just sort of dorky rather than scary. The writers learned well to lean into that dorkiness in later appearances and DS9.
What made the borg intimidating was you actually felt like they were a threat. I mean, pretty early on they captured and converted picard.
Riker attacked the Borg cube because of the danger to humanity and because of the known opinion of the man he respected; be quick and decisive against the Borg because they are inherently dangerous and a threat to humanity damn the costs.
>Picard isn't married, has no family or children, and apparently no desire to change that. He's actually distinctly uncomfortable around children. Instead he married his job, which is all consuming. Right there that renders the character boring, overly intense and unrelatable for many people.
about 11 percent of people in the UK claim to dislike children, 20% of them say they couldn't care less about them. 20% of US citizens claim to have no desire for having or raising a child. 44% of Americans claim they will prioritize their career and personal prospects over relationships and children for at least the next 10 years in their life.
Picardd's character in those regards seems to sit around the opinions of a third of the western world, and likely higher among Trek fans.
Also , regarding those topics, we see Picards' character finally and permanently turn into a man that prioritizes family life in S05E25 'The Inner Light', where he lives an entirety of a life as a dedicated family man before being flung back to duty.
Also the "crew doesn't care about Picard" concept doesn't fly at all. Picard routinely leans on his family-like connections with the crew, the Crushers, as a father to Data, Wesley, Riker , a mentor to Geordi ; hell he even begins treating Q like family by the end of TNG.
>Picard is supposedly a culture maven, but neither him nor his crew ever creates any.
One of the primary concepts explored in TNG is the struggle that man has to self-explain their condition in a meaningful-enough way to an artificial human such that they can reliably grasp the concept on their own and boot-strap into a human equivalent. Picard is instrumental to this. In a very real way that is a stronger concept of birthing culture than most of the xenocultural stories in that it's an offshoot of humanity directly.
>Picard says everyone on the Enterprise is there because Starfleet is prestigious and he seems fine with that idea. This arrangement could never work in reality so he comes across as delusional
plenty of non-terrible countries have conscripted service. I fail to see a major distinction. Plenty of Star Trek crew members object to things and get thrown into the equivalent of a brig/court-martial.
As for the economic/world-policy problems: most problems people have with the system displayed in Star Trek is that it's poorly explained, even if it's shown as working fairly well. I think that's a point to jump in with suspension of disbelief personally; but if you need a more realistic economic outlook then check out the newer Picard show or DS9; there's a strong, true, and relied upon currency and the world has mostly gone to shit because of it, explored ad nauseum.
I think the greatest defense in the fantasy of TNGs economics and policy is simply that the show wanted to explore topics further away from concepts that humanity was already entrenched within.