He wants to finish the game so he can release it on Steam to reach a much wider audience which = more $$$.
The game already has a lot of content in it with Linda 4/5, Caroline at 5/5, and Sara 3/5.
Finishing Linda and Sara + all 3 endings (harem + solo) is still a lot more content.
I think the goal for this sudden "motivation" is Patreon cucked him so it's on to Steam where things are uncensored and he will drop Patreon and start using Subscribestar. With a finished game on Steam he can charge a Premium since it's not ongoing and he can collect a second bankroll instead of making "monthly promises" to Patreon pledgers.