There does exist sore losers who only want easy guaranteed wins they don't need to work for.
However, most everyone will tell you the same thing; if you want people to stay, stop sucking (not you specifically, but everyone as a whole.) This is how things are, if people stopped being goons and played better we'd see far less intentional quitting. It's not right to force people to humiliate themselves in a meaningless battle where their teammates are running about like beheaded chickens.
Even still, there'd be work arounds such as jumping on an alt. And if you suggest such a "quitter debuff" be a global thing then...sorry, no thanks.
Nothing worth while comes for free, it has to be earned to have any value to it. People need to realize that 50% of the people in a WZ @ the end are going to lose. Nothing can be done to change this fact. Either you play the WZ or you lose. If you leave early, then you don't deserve to be able to continue to play WZs, just as if you leave a FP you don't deserve to continue playing FPs. There needs to be some consequence for leaving a WZ. Also there already is an Auto AFK status, just shorten the time it takes to enter it, at least in a WZ, and make entering it in a WZ auto-kick you from a WZ.