This game has a lot of positive points: an interesting story with humor, a nice gameplay, beautiful graphics, sexy and endearing characters, precision work (for example with the animation of the breasts), updates with a lot of content, etc. Runaway Princess is a unique and special game.
If Mobum doesn't have more patrons, it's only because the first subscription tier is $5 and as said before, not everyone is aware that the payment is by update, since patreon subscriptions are usually monthly.
Personally, Runaway Princess is one of the best adult games I've ever played, and I'm tired of seeing people complaining because it has avoidable NTR or some bugs that will eventually be fixed.