sodakknight: To my knowledge, there isn't any stat or prize for number of stroke play games won.
True. Nobody outside will ever notice who "won" - not even the "winner". It's but a long-time flaw.
sodakknight: The only thing playing a stroke play round with someone else, whether they quit or not, gets you is a little more XP.
Unfortunately, not true. The final bonus is given for the final game status, so if a player finishes solo, it will award solo XPs, not more.
sodakknight: Playing a stroke play game can also certainly [...] harm your own average
Unforunately, this wrong belief leads to quite a few quittings.
It's not true. No bad score would harm the average on the long run, because it's wiped out anyway after saturation.