Yeah, this idea is just asking for trouble. It would encourage more games like BB, and I know, you've said "good games" would be rewarded, but that simply isn't true. What makes BB, MotH, and similar titles so popular is that they function on the same risk reward system as gambling. That system triggers a psychological event known as Sunk Cost Fallacy. So long as there is just enough sexual content to make the grind seem worth it, you will play and play and play just to get that gratification in the end. Meanwhile, the amount of time and energy you're devoting to each "win" rises exponentially in comparison to the value of each win.
In short, it would encourage porn games to become more and more like mobile games, rewarding you for spending hours doing nothing by giving you some new content, and then constantly making the grind harder and harder.