The accusation of fetishization gets thrown around the m/m romance community a lot, and often in pretty sexist, and even transphobic/homophobic ways. BUT it is important I think for straight cisgender readers and writers to think very critically about the way they talk about queer bodies and queer sexualities within this community.
I am not saying this always happens when gay romance or any other kind of LGBT romance is written for a cisgender heterosexual audience. But it is a lot easier to reduce a gay couple down to the fantasy of two hots guys, a lesbian couple to two hot chicks, and trans people into sexual fetishes when you assume the actual people represented will not be the primary audience for these books.
Speaking directly to a queer audience will limit the amount of time a writer will spend describing queer identity and queer bodies as strange, exotic or Other. It also becomes a lot harder to fall into the trap of dehumanizing a gay, lesbian or otherwise queer couple, if you write with the intention that the majority of readers will be themselves queer.
I also think speaking directly to a presumed queer audience will encourage cisgender, heterosexual authors to police themselves, and think critically about their internalizing homophobia, transphobia and their privilege.
–E.E. Ottoman on why the “m/m is for straight cis chicks!” trope needs to die.