Personally I would say most people here and in tech communities in general are insufferably rude but YMMV.
There are the exacting, detailed oriented, pedantic, focused engineers who just cannot think big picture. They're great at rules based / systems following work - and love picking apart anything not based in 'immediate reality'
There are the strategic, forward thinking, open minded who cannot execute a project to save their life.
There are the directive, steam rollers who bully a team - but great at getting stuff done.
Etc. Etc. Other types, but for brevity I cut it short.
Engineers by design are used to problem solving or working through the problem solving. If they're not solving the problem - then they would be in "what's wrong with this approach" mode and some may see it as rude.
Tl;dr: they aren't all being rude, sometimes it's just different styles of communication and sometimes they're compatible, and sometimes not so much.
(And sometimes they are being rude, and sometimes they maybe can't help it...)
One can come into contact with many of the same "rude" type, but it's generally due to the fact that hiring in any given organization is generally based, at least in part, on "cultural fit". This means the various types of engineers will tend to segregate a bit over time. For instance someone who is a bit more contemplative may not meet the "cultural fit" requirement at a crypto defi shop, but might do well at a national laboratory. (And vice versa). This is why we shouldn't meet a group of, let's say "strong personality types", and assume that all engineers in other places are similar in nature. That's not at all how it works.