Maoraigh1,
I think the issue with Youtube is that, in general, those who comment are either young kids with a tiny bit of knowledge who don't yet respect the freedom that anonymity gives them, or people who go on there with a few keywords in mind to punch into the search engine (on their chosen subject), with a mission statement of spreading their 'superior' knowledge all over the domain in an attempt to be the best armchair specialist out there.
Your point is very valid though, I agree.