Yeah, seems like an easy way to cheat; reconnect after 4.5 minutes and hope to win by default.
As I am a terrible player in real life also, I finish my WGT games no matter how badly I am losing.
I have had to quit a number of times myself (wife nagging, kids gagging, etc.) but always use 'suggest drop' or 'concede' if the other player likes.
No, I am not saying I am nobler than thee, what I mean is that it's just a game; why bother cheating? It's not as if you'll get invited to the real Masters if you have a tour master rank here.
However, can we have a stats option when a player joins a game; when you show his rank, show played/quitted games alongside that?