Originally posted by Fierais: Winning against a hacker shouldnt be a punishment to your elo? Tell me how that makes sense ubisoft

We explained this a bit in our Dev Blog.[www.ubisoft.com]
The whole point, as the others have mentioned, is the system revokes any MMR that was impacted as if that match never existed. The system takes back any MMR you won while playing with a cheater, and gives back any MMR you lost while playing against a cheater. We mentioned testing a one-sided MMR Rollback system and found that it could potentially inflate MMR, which we want to avoid.
However, we have been taking note of people getting upset when they lose MMR for overcoming a cheater. Hope this helps clear it up a little!