There really isn't a great way to handle this. WGT survives by as much play as possible and locking people from playing isn't good business.
Once you achieve the top level your average doesn't mean much so you don't see much quitting from the Legend group. I see most of it from the pro and master level who are trying to get their average as low as possible so they can move upward, in reality they should post every score so they would be in the proper tier.
I generally play 3 to 4 stroke play games with lower tier players each week, just because they enjoy seeing a Legend show up and it is always interesting to me to see who the newer players on the site play. After my 9 hole round with four pros last night, I might have to rethink that.
We started, front nine at BPB, with myself and 3 pros averages from 71 to 79. The first hole took about 20 minutes to play as they hacked around the rough and got on the tournament speed greens. One player dropped out on the 6th hole, standing 8 over for the round. The second player dropped out on the 8th hole, standing at 13 over for the round. The final player managed a par on the 9th hole to come in at 16 over par. The round took over 1.5 hours to complete. Hopefully players like these will post all their scores and not just run to St Andrews and only post the 32 that they shoot under easy conditions.
The original point of quitting in alt shot, there is no excuse, you ruin a game for 3 other people. At least in the stroke play round I could finish with someone or alone. My thought on penalizing people who quit was by taking away points used to level up, I know some people get disconnected but it is what it is and taking away 5,000 points for leaving is incentive not to do it and the few times you get disconnected and can't get back, then that is just like a meter freeze, it happens.