You shouldn't be judging this as a bug. There's a reason why you have to pay half of the total Energy with your enter and the other half when finishing it. If you'd be implementing a countermeasure, you'd drag those down who cannot resurrect and they'd lose EP then, becuz you wanted it like this?
Furthermore, shall they loose Ep whenever they die? Like, when there's some1 dying in one of the Mob groups, shall they loose EP too? Cuz these People would just die with one of the mob groups instead of dying in the Boss room to save their EP. And now imagine you had to choose between EP and a Resurrecter in a mere Mob group. Not a really appealing election, huh?
At the very least this whole QQ made me at least fight the Boss with them. I just won't use pots. It's a good training for dodging. You can only appeal to those people, that they at least help you with the Boss. The other methods just have way 2 many flaws. Especially if I consider the arrogance shown here, by complaining about them beeing selfish, but not even considering what the bad sides of "removing this EXPLOIT" were. ^^'