I think this is a common misconception, perhaps amplified by popsci and the media stoking outrage. Granted this is anecdata, but I belong to a family of scientists (myself, both parents, spouse, one sibling, his spouse), and live in a town where you can't spit without hitting a scientist.

Most scientists are just "normal" people like everybody else, and are vastly more aware of the difficulty of getting things right in scientific work. Get to know a few of us!

As for the topic of the thread, I think "stupid" might be an extreme term, but every scientist has experienced being wrong about things, over and over again. But it's a different kind of wrong: Being shown that we are wrong by Mother Nature, because we invited her to do so. On the other hand, the only "wrong" that most people outside of science experience is anticipating the wrong side of a choice of humans that is ultimately arbitrary, subjective, or random. The difference is being rationally wrong, rather than being socially wrong, for lack of better terms.

What I think makes prominent scientists seem "arrogant" to the public is that they expect us to behave as if our predictions are ultimately decided subjectively, i.e., to hedge our bets, and to give social encouragement to both "sides" of an issue. We don't give out participation trophies, nor do we ask for them. If I'm wrong about something, I'm not "wrong but tried hard." I'm just plain wrong. I'll be wrong again.

The vast majority of scientists I know (I'm a scientist also) are self-doubting to a fault and often feel stupid even if they're not.