I can burn a stack of Runecloth Bandages per raid. Healers are too busy to bother with my disposable Rogue. That's a 2k heal I can use in combat(half my buffed total life), which is done in 8 seconds, probably before I eat the next AoE or whatever crap the boss does. The only good alternative is a potion, which heals for less, costs more, and has a 2m CD(bandage is 1m). The good news is that they do not share a CD, meaning both can be used.
My other best use for bandages is to heal my Hunter's pet. I need mana to SHOOT. If I'm going to stand here uselessly channeling a heal, I may as well not waste mana in the process. Bandaging your Hunter pet is probably the game's best use for bandages. Mend Pet just hogs mana to do the same thing a bandage does for no mana.