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?
Seems like the answer has to come from raid leaders -- if your guild is losing morale by beating your heads up against nothing but hard modes and progression content, it's time to dial it back a bit, and do a couple of farming runs instead. Especially in a 25-man raid, even downing the normal modes of most bosses should net your raiders some piece of gear they need, and pushing players to do bosses they'll wipe on all night leads to more burnout, even if it does net you some guild first downs eventually.
It's interesting that players always seem to be fighting to raid a tier above what they're really capable of -- I remember even back when we were raiding halfway through Molten Core, my guild would schedule a night in Blackwing Lair, even though we never did anything but wipe in there. Maybe the separation of normal and Heroic in patch 3.2 will help slow down players a little bit, but you have to think that, by now, Blizzard should know that players will grab for the best gear they can.
Patch 3.2 will bring about a new 5, 10, and 25-man instance to WoW, and usher in a new 40-man battleground called the Isle of Conquest. WoW.com will have you covered every step of the way, from extensive PTR coverage through the official live release. Check out WoW.com's Guide to Patch 3.2 for all the latest!