Why do fans hate the idea of "playersexual" Companions?

Ok I was going down a rabbit hole of veil guard news and whenever a video or topic of the companions all being pansexual (or as the rpg community dub it "playersexual") the most of the community seem to be against it and Im honestly curious as to why? It seems to me the common consistence is that it's 1. Immersion breaking 2. Not realistic

Now for me personally having the choice to make or play the character I want and being able to romance the companion I want really increases replayability for me. But would love to hear other people thoughts on this