The ceiling for male protagonist harem games is much, much higher than that for female protagonist lesbian games.
That said – the floor is much lower as well. The overwhelming majority of male protagonist games has less than 50 patrons if they even made it into the double digits within the first year or so of their existence, while many lesbian games get a small (compared to the high earners), but very loyal audience in a relatively short amount of time since the niche is starved for content.
Devs who are in it for the money will probably end up miserable on both sides lmao
it's a bit about supply and demand, as there are so many straight games, the good numbers are going to be maintained in the most outstanding ones.
lesbian games, because there are so few people interested in them, make them few, but that makes their audience quite loyal and makes profit "distribution" less "uneven", maybe these devs don't earn as much as the big straight games, but enough to make it an extra amount.
Generally what I have seen is that lesbian devs treat it as a "hobby" or at least as a second job where they earn extra money.
while the many of straight devs try to make it their main job, but of course very few actually manage to accomplish that for all the competition out there, as you say the devs who are here for the money will probably end up miserable (reality always hits hard XD).
and well apart from that there are also the straight devs who do it because that's what they like, which adds to the great disparity between the genders.
maybe i'm just talking nonsense, at this moment i'm taking admin subjects at the U so i'm in "admin" mode XD, but i'm kind of understanding it that way.