it really is stupid. an all guy harem around a woman is still a harem. its been that way since ancient times. I was an english major, and a writer, so seeing words abused and misused like this kinda ticks me off. It's basic knowledge dammit.
Harem is a loan-word from Arabic or somesuch, isn't it? In reference to the area of the house where the women are hidden away. Traditionally speaking I can only have seen it as referring to women... but if it is more about the act of keeping them locked away than the inhabitants themselves then I suppose it doesn't make much difference.
I can't see as being an English Major would make much difference in that case though, since the word has already been warped in meaning since its original adoption.
Either way I'd say how you choose to use the word would depend on which way is the more practical. If you see a word in another language or culture that seems more useful than what you have in your own... take it and use it. If you see a word that is utter fucking cancer and hate it... then reject it.
And also the term "reverse-harem", while it fulfils a purpose of distinction, is a pretty shit term. But then I don't much care for the word "harem" in general. There just happen not to be a lot of useful alternatives. The word "seraglio" sounds far more elegant, but that word still has its original meaning and hasn't been mutated the same way "harem" was.
Plus everything gets confused when there is a Bakarina scenario... i.e. non-gender-limited.
Harem meaning as per "merriam-webster.com" dictionary,
If Merriam Webster says something, it should probably be regarded with extreme scepticism.
Lest we forget they're the ones who decided that "literally" was the opposite of itself. They condone the active destruction of language. Ergo they have failed in their role as a dictionary. Public toilet graffiti would be a better source for language than Merriam Webster.