Lae'zal will **** anything that moves. so will asterion. so will shadowheart. So will Gale.
Roll it back. For example, if yo aren't gith, Lae'zal won't touch you.
Shadowheart romace DC for women is 10, and for men is 20.
Asterion has racial preferences and won't touch certain races.
Gale has a CHA requirement.
To add a depth to the game that makes you want to roll a character just to explore the depth you can't get if you play a certain way.
That would be closer to how the Baldur's Gate 1 and 2 approached it. Not exactly... but this is BG3. not divinity. And I will compare this game to BG, and not divinity. As will many here, that are here because they fell in love with BG.
First of all, of course players should have several romance options. On the other hand, they also need to be believable.
A githyanki would usually be "evil", and even if Lae'zel is not, it should be really hard to score with her, if you are not a gith. Maybe not outright impossible, but really hard.
Shadowheart is meant to be this evil cleric cult, right? So, maybe she should prefer evil characters.
Asterion could potentially work as a bisexual character, but as someone else pointed out, only do that if it is actually in character, don't blatantly invent characters to shove some ideology in the face of players.
Gale strikes me a womanizer, but otherwise easy to win over.
-> again, romances should be possible, but not forced. Don't try to desperately write a romance that's not in character.