Playersexual is simpler to implement. It is easier to have a blank canvas for romances and given it is a less important aspect of the game (arguably this is a crpg not a visual level) that is why the Dev went that route (this and avoiding backlash from any vocal minorities which make for bad PR).
It is also, objectively, an inferior path Vs. having predefined and rich back story for each NPC.
The issue and the awkwardness comes from the facts:
1. as noted by OP, Larian did actually flesh out the backstory of wyll and gale establishing them as likely not just playersexual.
2. maybe to due to bug or not companions are currently heavily hitting on you regardless of your gender.
I think 1. is fine after all the majority of the players would likely setup these characters to follow Larian path and if the incoherence affects you because you play a gender neutral tiefling with a woman body and male genitalial... Well it is on you.
2. Is I think the root of the problem. Interestingly my wife view was: "well being a good looking elf woman in a group of men will likely lead to a few unsolicited demands". So in that setup unwanted solicitations, some might say mild harassment, might be questionable but sort of realistic. The goofiness is coming from SH also being interested or wyll and gale hitting on you as a male. If think a very easy fix here which will go a long way on satisfying everyone is simply to add a sexual orientation for your character when you define your sexual identity. After all we can choose genitalia, gender, body type.... The lack of sexual orientation is a glaring problem.
I don't think it is controversial at all: we will still have non mainstream relationship portrayed in the game (e.g. Isobel) and it is solving all the controversies on that front.
Food for thoughts. But given the number of threads on that topic it is a simple implementation. Flag the orientation (male, female, any) and block the opposite romance path.
