That's very odd to me. I spend a lot of time in online communities and I've been hard pressed to find anything as welcoming and helpful as Stack Overflow. I became a high rep user over the years, and I made mistakes that earned downvotes, but usually someone could give me a pointer to how to improve my question or answer. (Not always, but usually.) It does suck to get downvotes, especially without a comment about why, but honestly, when I look at other sites (ahem hacker news) where the rules are only ever referred to by experienced users and in tiny print below the fold, the clear rules and help on StackOverflow, and posters who are willing to link to them and clearly explain them seem like a breath of fresh air.

I haven't spend that much time asking questions, but I answered many (and commented, edited, flagged…) but Id didn't found the community that toxic, especially compared to other places.