DJWheat was supposed to be the moderator in that discussion, but he went way overboard and just flipped shit.
More importantly, he was acting as a leadership figure in League of Legends, and a lot of LoL fans were expecting him to be the head of representatives for League. However, in this video, he couldn't stop expressing SC2 as "the better game" so he lost a lot of fans from League.
Of course, he also lost a lot of fans from SC2 for saying it is doing great, and then jumping over to LoL.
And then he lost a lot of fans all around for being really immature.
Destiny not only was correct about everything he was saying, but his "improper method" as they all said it,
worked. Did we get chat channels because Blizzard thought a year in to release "oh, we just noticed we dont have chat channel!" or because people whined and bitched for it? And here it is working again. You could argue that the community uproar was caused by Destiny, but it really wasn't. He was only the catalyst to what everyone has been feeling for the longest game. With that outburst, Destiny was contacted by a Blizzard employee promising changes, and now look what we have.
http://us.battle.net/sc2/en/blog/7681240/Heart_of_the_Swarm_Preview_Leveling-10_25_2012
And this is only the first of many features promised to be changed for attracting the casual audience. But Destiny said on his subreddit that he's not really impressed. In either case, its a good step forward, and it would never have happened if we, like the EG house suggested, kept quiet and did "our own things".
He is being criticized for that "low blow exit", but the EG frat house ganging up on him that whole discussion, along with Idra saying "Go back to fucking LoL" and then inControl getting up to high five him really pissed Destiny off which led to the comment.