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...)