I don't know about other warlocks, but if I'm not doing end game content then I'm going to be running as a void walker anyways and if I am doing endgame content it seems pretty obvious to me that fire born is way more useful than an extra couple of grenades. I could see how it would be more useful to run this way in pvp, I've never understood why warlocks have self res on in pvp, it makes no sense. Ok I can see how it might help for trials to be able to self res but for normal crucible, you should be using your super to maximum effect, choosing where and when you pop super is a big part of that, if you're waiting until someone has killed you to pop your super? Well let's just say that doesn't seem optimal to me.