I did not try to imply that You want to start a flame war. It was rather general comment about youtube comments, because they are one of worst possible places to start discussion about any topic, the other one being 4chan.org/b/
I didn't watch twitch one, but again it was rather general comment, that this forums are the possibly the best place to start discussion and get constructive responses
And when it comes to the typos, if there are many, speaker in collaboration with uploader can probably superimpose annotation in youtube video where there are typos, but they have to know about them. And the best way is to inform either speaker or uploader of given video.