Q syncers/trolls/noobs

Hello,
So, you are meant to say that a person playing a DC priest at MMR of 2.1k is not capable of healing more than a prot warrior?
How is it even possible, Blizzard? How troll is this?
Or is it just a q-syncer?
Isn’t it weird that my games are pretty decent, difficult, but actually fun and winnable, and at some point my winrate becomes higher, so you will give me such teammates to get my winrate back to the sweet spot of 50%?
I mean I dont have anything against people who actually play the game and try to do something and make mistake sometimes, but that person, I am sure, was not doing anything. He was purely trolling or wintrading (at the MMR of 2.1???XD)