First, i will say that as a game designer of a particular genre of game, you should be doing your homework and at least casually checking out the competition, thats for sure.
Second, I will disagre with you on one point. WoW did in fact singlehandedly destroy the entire genre of mmorpg. So at least on that point Brad was correct.
I don't think they destroyed it. They found what a vast majority of gamers wanted in an MMO and made them that game. It was a fantastic game in vanilla but the audience wanted easier and they gave that even at their detriment. I believe the other developers destroyed the industry because they either copied WoW too much or made inferior games. WAR could have been amazing, but they didn't fix issues from Camelot or improve response time for a PVP game. RIFT was amazing until they took out the best parts right before release. That's not on Blizzard, Trion fucked up. GW2 focused so much on PVP that a beautiful well-made game had nothing else to offer. It was very MMO-lite. SWTOR was a worse version of WoW in space with voice acting. Not enough of a lure but very successful short term.
People think WoW killed the genre because their favorite game of yore died off. Usually(always), it was because the developer fucked up.