No thanks. Changing it from wins to participation would lead to a lot of people just being AFK or trying to throw the matches so they end faster. Clearly you don't care about the overall quality of matches where people actually try to win.

I tend to get more wins each week than 2nd or 3rd place. It could be because I'm willing to switch to healer when there's none or only 1 in the party. Maybe you should too.