I suspect much of the complaint is due to two things. Making the companions "player-sexual" and having many of them initiate romance/sexual encounters.
I'm not sure it's exactly the "Player-sexual" thing as much as it is characters being designed to appeal to the majority. I.e. The lack of racial diversity between companions (With the datamined halfling werewolf gal getting cut from the game)
Which is somewhat surprising given the diversity Larian had in DoS, with the roster including a dwarf, a lizard and a skeleton who wears faces. With the argument being made that the reason for "Elf, elf and more elf" companions is so sex scenes aren't too weird (Ironic given the whole "Bear sex" thing, not to mention mind flayer sex...)
But yeah, the companions initiating romance seems to irk some people, seemingly because they feel uncomfortable when people not of their preferred sex come onto their character (Personally, I've had dudes hit on me in real life and it's never bothered me. I just politely tell them I don't swing that way and we both move on with our lives). Though there is the whole aspect of simply trying to be friends with the companions and then they're suddenly like "I wanna ride you", which is exacerbated by the fact that basically all the companions end up like this (If it was just 1 or 2 that made the most sense. For example, Karlach who's not touched anyone for years and Lae'zel who's direct and comes from a society where sex isn't about reproduction it's entirely a recreational activity)
