If someone goes 0-6 in rated solo shuffle, others should never recieve CR/MMR drop

That’s literally how it’s working right now, it counts each round as a match. The system is, it’s not me saying it.

As for why you need to be punished, there will be differences in people who can carry that person, while others can’t, and so on. So the rating system will separate you from those who can, by causing rating loss for you while rating gains for them.
It’ll occur in other shuffles if that person got 0/6, sure, but the point remains the same.