There's nothing wrong with wanting harem endings, and harem stories don't preclude good stories and good writing.
I like harem games, but I agree more games could do with more varied reactions to the player character. A cast where all the women are playersexual can be very annoying.
Having a lot more, and varied, lgbt characters in games would help flesh out the worlds and balance things out.
Some girls are going to be lesbian and so completely and utterly un-romanceable by a male MC. That's life.
Some girls being lesbian would make the bisexual girls feel more grounded. Their attraction to multiple genders feels more genuine rather than an extension of all women being attracted to MC.
Also, let there be gay and bisexual men in game, let them be attracted to MC. I'm not saying MC has to be bi, though that would be my preference, but especially in games where MC magically attractive to everyone, it should be everyone who is naturally attracted to guys.