The % is strictly a tool for your prospective opponent to determine the odds that the game you are considering will actually play out to its conclusion. It reflects disconnects for any reason, intentional or not. Unintentional disconnects and drops should occur at approximately the same rate for everyone. If your situation is uniquely different, causing more disconnects than other people, then your opponent should know that. Otherwise it should level out for everyone and a good % for "non-quitters" might be 90 or 80 rather than 100%.
If WGT can fix the problem of the % dropping for those who remain in the game it will be a good tool to have, but right now it's meaningless.
It is not labeled "Quit %". It is players who are incorrectly reading it that think it's labeling them as quitters.