My warrior isn't high enough to do raids so I can't really compare it to my ret paladin. Just comparing to soloing, I guess I don't much care that I have to build rage to use my abilities vs starting off with a mana pool. With a ret paladin, I can go on pretty much infinitely, whereas with a warrior, I HAVE to keep attacking something to ensure I have enough rage to use my abilities.
I guess it's just a matter of convenience. With a paladin I can keep attacking things and self heal. As my warrior, I have to keep attacking things to keep rage to use abilities, and if I have to stop to bandage or something my rage is down the chute and I have to start all over again.