It has become pretty clear that a lot of folks are only interested in staying in a WZ if it looks like an *easy* win for their weekly, because at the first sign of trouble they are gone...I'm sure in search of the easy win elsewhere. It is becoming endemic on my server. Without fail if the other team caps two first or scores a point first, etc. three folks are gone in a snap. They don't even stay around to see if it will be competitive, they just want an easy win.
I think a five minute time-out penalty to re-join another WZ when you quit or eliminate the Wins requirement for the weekly is in order. I prefer the penalty, and I know folks will say "but some people disconnect all of the time and it would be unfair." Hey, it is a five minute penalty...do something else for five minutes, like call your ISP if it happens all the time.