This is one of the few seasons since WotLK that games are super fast and fun.
This 15% debuff is a good thing, without it, warlock and dampening teams just run people over.
There will never be a perfect balance where dampening teams and fast teams can co-exist. Let games be fast rather than 10min dampening fest.
You srs? The 15% healing nerf is the reason locks run every team over rofl