For me, it allows for offline play, whether that's because my internet is down for the 5th time this month (thanks AT&T) or if Itch decides to purge the site of fetish games. Maybe I'm a Luddite, but I dislike trusting web only infrastructure for personal stuff.
it's a mix of A. wanting to have the game offline, itch can be a bit wonky with this type of content. and B. because i enjoy modding games, looking at how they are made and adding my own content. so i would appreciate it if you were to add a download but no worries if not. great game btw.