Mmm it's more that they feel they're being fetishised instead of being seen as whole people. Cis women don't like being reduced to a vagina either.

Like, trans people don't want to feel that the only thing about them that you like is the fact they're trans.

Just like cis straight women don't want to feel that the only thing men want from them is a hole to fuck.

Yes having an orientation means finding certain body types attractive but just because someone is straight doesn't mean they would fuck anyone from the opposite gender. Being gay doesn't mean you would fuck anyone from the same gender. Being bi doesn't mean you would fuck everyone.

Attraction is a lot more complex and layered and involves appearance, behaviour, personality etc.

That's the difference between healthy attraction and fetishisation (which is focus on one small aspect of a person to the exclusion of others).

Fetishes can coexist with healthy attraction of course. But people don't want to ONLY be fetish objects.