I main a warlock because I like the playstyle. I don't enjoy the titan much but I started as defender then sunbreaker and only recently started striker. Hunters have the best supers for crucible though. Warlocks ability to rack up multikills is wrecked by every hunter super. Nightstalker is so clutch and incredibly frustrating on the other end. If you play objectives like control and rift, you can make a huge difference. Statistically titans suck at crucible. That's a generalization that doesn't mean all titans suck but rather most bad players want to break suns. I don't think anything really needs nerfed. Bad players will play bad, good players will play good.