I think many players would agree that losing more rating than winning is a bit disheartening. You could win one game, but lose more in one loss.
Currently, a 66% win-rate is essentially a 50% win-rate in terms of rating, and the ratio decreases the higher you go up on the ladder.
There are adverse effects of this situation. For example, a player will refrain from playing beyond the required amount of games necessary to place on the leaderboards because of the effect of one loss. The risk of losing outweighs the gain from winning, so there is no incentive to play more PvP.
In my opinion, changing the ratings gain/loss would let players be unafraid of the risks of losing, and continue to play and hope they will net a positive ratings change, boosting the PvP population beyond what it is currently.
I don't think the inflation in rating would adversely affect the quality of games in any division. It should be the same regardless.