The issues with Epics this late in the expac are similar to the problems at the end of SL. The NPCs and vehicles are way too easy to destroy, and if you lose the initial clash, it is tough to recover, so most people on the losing side give up. Out of a team of 40, it’s common for 15-20 to leave after the initial loss, and people who queue in afterward feel punished. I don’t know the solution to that problem, but one thing I have seen mentioned is giving the losing team a surrender option where everyone can vote. I like that idea more than punishing leavers with a longer deserter debuff.
I think that would help some of the animosity players feel towards the large premade groups, no one wants to spend 20+ minutes in a battleground they know they can’t win being farmed by a coordinated team.