Nobody is quitting because of relics per se. People are quitting because they are bored with grinding gear. This is a collection/grind type of game, not heavy on action. So if you want action, download something else to play when you are done simming your daily grinds.
And yeah the relic system just isnt much fun. You are doing the same thing you were already doing, simming nodes to get gear. The only thing that has changed is cantina where instead of simming nodes for characters you now sim for scavenger pieces.
What I found disappointing was here was this new mechanic that was introduced and there was no new game play from it minus the scavenger which is cool visually. Do relics make me want to quit? Nope, but they certainly have nothing to do with wanting to play. Cant wait to get a node where I can actually use characters just for fun, Blitz perhaps?