Did Nost buff the old raids in any way? Because if so, sure, I can kind of understand why people are so picky about their raiders (Even if it's still a bit silly,) but if not, there's really no reason for the rampant "MUH BUT HYBRID" mentality that keeps going around.
I raided way back when, and at any given time you'd have 10-15 people either not paying attention, DPSing poorly, or playing "unviable" classes. The raids simply aren't tuned so tightly that you need a full 40 man roster of warriors/mages/rogues and nothing else.
Seriously. There's really no reason to be super picky.