Yeah, because the fusion of 2 of the best guilds in WoW's history (no offense to EJ) is representative of the hardcore people that wanted a challenge?
Also, didn't they spend the whole 24 hour clearing the instance? And didn't they get a lot of practice already in PTR?
Also, they have downed Yogg-Saron, but if we compare Ulduar to Karazhan, Yogg-Saron would be Prince while Algalon would be Nightbane. Nightbane is much harder than Prince. Plus, they haven't even done any hard mode, I'd guess.