You won't see most of these incidents, because harassers do it when there are few witnesses. Ask your female colleagues for their stories. They all have them.

So how does this fit with your "Most of the engineers I know in tech are decent, upstanding guys." - it fits perfectly. Clearly you know some who aren't decent. It only takes one to harass, and he can harass a large number of women; in fact the pattern is commonly to try it on with every woman, but in a way that leaves it as he said/she said.

This is why "not all men do this" is such a weak-minded response. Don't let it slide. Your second guessing of women in your first point, and your "too easily" in the last indicate the problem too. Women who report harassment often get laid off or managed out afterwards, even when they have got the harasser fired. It is a very high risk thing for them to do, and your "not all men" attitude is a key way that harassers are sheltered.