I wanted to reply to some questions below, but realised I've got more touchpoints than any single one of them.
Every now and again, I go through spurts of activity where I try and contribute to SO with reviews, comments, edits and answers (rep a bit below 2k). Two things happen every time I do this:
1. While there are lots of 'please do my homework' questions by new users, every now and again someone will post a question where they are genuinely trying to get their head around a concept as a new programmer, even though the question doesn't necessarily meet the MVP requirements, or could be seen as too broad or off-topic. I try and engage in the comments section, and quite often, it turns out to be a viable (but poorly asked) question, worthy of a good answer. The amount of aggressive downvotes, abusive comments, etc in these cases by other users (new and old) is absolutely astounding.
2. When I post answers, I try and tailor them to the OPs level, so it might not be 'by the book' accurate, but will explain the basic concept and offer a possible solution. For some reason, especially on C/C++ based questions, any answer that is not referencing the C/C++ standard and absolutely factually correct and accurate in terms of terminology, etc, will get aggressively downvoted, or destroyed in comments. What this has done, is to effectively stop me from even attempting answers in these categories.
So, yes, there are lots of 'bad' questions and 'bad' answers, but generally the voting and moderation system works. However, I think that 'older' users are as much to blame for some of the issues on the site, as new users who come there to have their homework questions done.