you need to fight for 3 min before it applies, so you cant just go and wipe, and buff up.
it would take 15min to get full stack, in that time you could already have killed it, normally. so timewise, there's no reason to buff up to ignore mechanics.
So you can't just stand around waiting, like for ADS to enrage.
If you can survive 3min, there's no reason to wipe, to make next attempt a little easier.
On the contrary, HC ppl will get annoyed, and quit, if you wipe on purpose, since ppl here are whining about the buff, to begin with.
HC ppl will get rid of buff, and crappy ppl will still die, regardless, cause of mechanics, so it doesnt make any big difference.