I think there should be some sort of positive feedback mechanism on accounts. Like you can either commend people or some sort of star rating system where you can give them 1-5 stars. We have forms of Negative feed back like block listing and reporting people but there is not much positive feedback for accounts. Then there could be an overall star rating on your account based off the average you get, guess that can be either negative or positive thou. Commends are probably more positive feedback mechanism.

i like the idea but it might be open to abuse
Maybe less so if nothing was shown until you had a certain number of feedbacks
And maybe lose the top and bottom few like in skating etc at the Olympics
Abuse would be ...
Some players are sore losers and even more so if it was a tight game or they were winning and then lost
Plus mates could just rate others as top in a rating exchange

Hm, there (sorta) are two positive feedback things in place. The first being a friedlist and the second being the clan. However they are both quite lacking.

There is a somewhat hidden 3rd thing as well. When you create a game, in the invite players tab: your friends are sorted by number of common games. Not sure I would want a public 'reputation' system. But this uservoice is quite popular : https://warlight.uservoice.com/forums/77051-warzone-features/suggestions/1142113-add-a-friends-list-subset-to-the-invite-list