Perhaps this distinction does not seem like it matters but I predict in the future this distinction will be extremely common (in humans at least).
It’s very common in sexual health because “men who have sex with other men” is much more useful when reasoning about disease spread than peoples wide gamut of self-reported sexual orientations.
There are definitely gay people who get married and have kids though. An alien who doesn't understand humans might classify them as heterosexual.
What purpose does this distinction serve?
Consider: https://en.wikipedia.org/wiki/Men_who_have_sex_with_men
I'm personally in the camp that if you have sex with genders outside the opposite of your own, then you're either gay or bisexual. I don't differentiate between whether you're attracted to the same sex or just seriously, uncontrollably horny and desperate to shag anything with an orifice.
I guess I still don't see the relevance of a distinction beyond that of psycho-semantics.
Who am I to say why an animal who's mind I have no insight into is having sex? I wouldn't even dare to begin supposing pretending I have any idea of what's going on in an octopus' mind(s).
(Although I did once read a fascinating fiction on some blog about exactly that. Can't find it now)
Sexually attractive? Well yes, if you're humping it you find it sexually attractive.
Psychologically attractive? Only if you have some kind of complex against being labeled 'homosexual' or 'bisexual' while still engaging in coutius with other people of the same sex.
Emotionally/Intellectually attractive? Well, personally I don't find myself sexually attracted to people (and in effect, things) whom I can't satisfactorily engage with on an intellectual and emotional level. I know some people are different and will fuck anything that moves. I've had people tell me so themselves. But I don't think the "Men Who Have Sex With Men" label discusses intellectual stimulation as a stipulation.