shadowdef, kill mobs of bad guys for as long as you want - does not make a game into an RPG. What you`re suggesting is an MMORPG.
RPG`s are games where your choices of doing things alter the end result of the quest/game and not about killing bazillions of enemies, take Fallout 2 for example. The only reason why MMORPGs are called mmoRPGs is because there are quests, if there`d be no quests - MMORPGs could be renamed to MMOAction/Tactical games.
Please name the RPGs where you had respawns.