Well over half of the games here only include a windows version. Do you not want your games to be played by as many people as possible?
Based on my previous games, over 90% of players go for the web version. Probably a convenience thing not having to hassle with any downloads etc and I do understand that building for web is not always an option due to performance issues etc. And the rest that actually download a version are pretty much split 75% windows, 15% mac and 10% linux.
So all in all, you're missing out on getting potential players by only doing a windows version. Well, guess I only need to play and rate four games this jam...