Karl, writing over on the WoW Livejournal, has an interesting set of thoughts about hard modes and just how they work with raiders' morale. Hard modes are designed to give raiders something extra -- if you've conquered the normal modes of raids like Ulduar, hard modes are put in there by Blizzard to offer you some extra risk for a corresponding reward. But as they've become more and more routine, some raids are taking on the hard modes even before they've cleared the whole instance, leading up to a night of wiping on early hard modes, and then wiping on later progression. And wiping all night is never good for any raid's morale.
Of course, this is one of the causes for the way the Crusaders' Coliseum in patch 3.2 is designed: instead of having both hard and normal modes constrained to one instance, you can run a 10 or 25-man instance in normal mode all the way, leaving the Heroic mode open when you're ready to do some wiping.
But then again, think about what the mindset is here -- players are throwing themselves on early bosses' hard modes even when they haven't beaten the end bosses yet. It seems like most raids will take any opportunity they get for more loot, no matter how tough it is, and that's what's leading to all of this "glass chewing" Karl is talking about. Even if Blizzard gives players the option to run a normal instance without worrying about hard modes, won't players still just run Heroic anyway, for the better gear?