So, I think the whole "well intentioned but hubristic scientist goes too far, tramples on the feet of god!" trope is pretty stupid in a lot of stories (although I still love a story about a character playing with forces they don't understand if it's executed well). But I also think you really have to consider where the "mad scientist" archetype comes from before you write it off as purely anti-intellectual:

1. To a large degree the mad scientist is an updated version of the evil wizard. Victor Frankenstein, the prototypical mad scientist, was trained in alchemy as well as chemistry and biology. Very often (such as in this very post) their laboratories are depicted as being in castles or even wizard towers.

2. Frankenstein was partly based on the sort of people who robbed graveyards. The more modern 'howie lab coat, rubber gloves, and goggles' mad scientist exploded in popularity after WWII, probably because of people like mengele and the invention of the atomic bomb.

There's other themes present in the archetype of course (I already mentioned hubris and man's vs god"s domain above, but there's all the other stuff going on in Frankenstein too), but yeah. The 'mad scientist' archetype is a little bit like taking a normal scientist and removing their humanity and morals, leaving only their intellect and ambition/ego behind. A little bit like how a warewolf is a man stripped of all morals and self control, leaving only bestial impulses behind.

That's why they're evil/mad scientists, and not regular scientists.

Yes, they get confused with us evil engineers.