I think over all not having SBMM is healthy for the game. I love playing crucible but I quit a few months ago because no matter how much I improved, I always got matched against better and better players so it felt like there was no return on my time invested. Basically, no matter how much you play and get better with SBMM you will never feel like you are getting any better. Over time, this leads to frustration and eventually giving up. Yes SBMM helps noobs not get crushed in the short term, but it makes the majority of people quit long term (even the noobs).
TL;DR SBMM will kill pvp long term. It should stay in competitive playlists.