We're not talking about tanks, nor are we talking about the terrorists lack of armor. They're fighting a guerrilla war using homemade bombs. Unfortunately, these crude weapons are quite effective against poorly armored HumVees.
By now, the DOD should have figured this out and should be making the appropriate course corrections. If this requires converting existing manufacturing capacity to another purpose, so be it. It is a war, right?
I agree I think all Humvees should have had hard armor as basic equipment, but guess what... it wasn't, you can't just throw armor on a humvee and think it will work, armor is heavy, you also have to change the suspension and possibly upgrade the engine, for more horse power.. Its not just "hey bolt on this armor"