I've done hardcore raiding, now I raid flex. While hardcore can be exciting given a number of people with the same mentality and approach and effort, what I have found more important to me is friends. That's not to say you can't have friends in a hardcore environment, but I won't be tossing my friends to raid hardcore. Not all my friends are even capable of maintaining normal raiding.
Heck, by this point it's debatable whether I remain capable of or even interested in the additional challenge even if friends weren't a larger issue.