In general there is lower interest for fem protagonist games. And than, for some reason, devs decide to additionally narrow that audience by forcing sex content. I won't touch fem protag games where MC is forced to participate in any kind of lesbian content or involved with fat/older males. Others wont touch game if they can't go full lesbian route. Third group won't touch game if they can't go full straight route. And almost always, there is some kind of forced sex content which will kill the game for one or more groups of players.
No wonder those kind of games can't generate enough interest.