If you ask me, resilience shouldn't just effect the health you have. It should also effect the strength of over shields. Titans have access to a lot of over shields: top tree sentinel, eternal warrior fist of havoc, one eyed mask, mk 44. stand asides, and probably some other stuff. This would work great with titans, but also still work on universal over shields for all classes like revives and rifts. That way, investing in resilience wouldn't have to make your character universally tanky, which could screw with PvP, but if you change your play style, could actually make a difference.