I mean, Hetero Male Games are made for people who are only sexually attracted to Female, make sense they only work on hot females. Sometimes including hot males might even ruin the experience cuz it breaks the immersion.
Most games on site are like this cuz the population is a majority.
There's actually a bit difference here, almost no Hetero Male Game hv appealing male, unless MC is Female, even then there'll be more ugly bastards.
But some gay game will have appealing side-kick female (That's not sex-able). While enjoy their company, it won't breaks the immersion / no one is "threatened" by them.
TBH, I wish all devs could keep it this way:
Identify your Targeted Audience and make the game for them.
Don't try to "appeal to wider audiences", muddy the water and makes the game not enjoyably for anyone.
It doesn't matter if the Devs are male or female, what matters is what the intended audiences are, does the dev have related perspectives / experiences (Or if not, do they care to learn).
I don't think there are "Less Female Devs", looking at all those YAOI / Otome. But I guess there are way less Female dev outside of this genre, Since Females are less Nerdy & Lusty?

(Sissy/Futa/Trap/YAOI/etc are different stories, but they still appeal to specific Kinks.)
Also, I'm a bit curious, I thought Being Bisexual means you get the best of both world? You could enjoy Hot Males in Gay games, then Hot Females in Hetero Games?
Like The male in this game (Or any of Male Doll's game) is just OK for me, but we don't really hv many games to choose from.