No, it's famously a VC thing, and it causes problems for ordinary US people as well.
As a German (15+ years in the US) formerly in SF now in Seattle I see big discrepancies in what I perceive as genuine feedback from coworkers or the general public compared to what I'd expect back in Germany.
Of course VCs go even farther to keep all doors open. That to me is more of the same I observe from most folks.
A founder from a different cultural background seeking funding or advice from US VCs must understand the baseline US culture and then how to interpret VC behavior relative to that culture.
EDIT: To provide a specific example: What is considered polite encouragement to a Californian comes across as very strong / enthusiastic encouragement to a German. Polite is relative to culture. Initially people unfamiliar with the culture may take the words of the random Californian or the VC at face value - both appearing equally enthusiastic observed this way.
It's a bit tiring having to praise things you don't believe in to provide honest feedback. In German culture the strong separation between work persona (with a shared mission on behalf of the company / shareholders / customers) and personal life makes it pretty easy to be straightforward at work. People don't define themselves by their job unlike in the US (or certainly SF) where one of the first questions may be "what do you do (for work)?".
From my perspective US colleagues overcommit (say yes to too many things) but don't ask enough detailed question to design solutions that can be of high quality. I'm not surprised you'll find Germans frequently saying that something is crap :D Germans tend to be cautious upfront, asking many questions (to understand scope and to mitigate risks). This often seems unnecessary to the visionary leaders, but a tactician will understand the importance for execution. Nothing wrong with saying "No, we can't do that. But if we reduce the scope, or change this or that we could deliver something."
In the end there are many cultural differences that are subtle but profound. Invisible to either side and usually expressed as what appear to be individuality / personality differences. It takes a lot of experience to understand which elements must be attributed to culture.
1) VCs want to keep the door open for later by not outright saying "No.", since there's no incentive for them to do otherwise.
2) VCs follow the herd (need social proof), so they will often wait for that area to blow up, or wait for another VC will be the "lead."
3) VCs today would rather be late investors after the concept is proven and they can move hundreds of millions of dollars around to get even more hundreds of millions.
Also note that VCs like to imply that they have integrity, but that's often not true:
1) They've had meetings to collude against YC (documented in the press.)
2) Silver Lake Partners revokes employee shares if you leave before 4 years ("In it to win it.") (documented in the press.)
3) Shocking personal anecdotes.