That’s not even particularly uncommon, is it? I’ve actually seen people I know and otherwise respect reblog “critiques” of M/M shipping by people who are not “mlm” on the grounds of fetishization (in fact, I usually only see the expression “mlm” in this kind of context, which is why I put it in scare quotes; it might be a perfectly perspicuous term, but I’m not sure I trust the people who use it, so I’d prefer to say “gay/bi/pan men” if I need to refer to the same set). Indeed, I’ve seen it enough that I occasionally question my own M/M shipping habits. If I ship two men together because I think they’re both hot, am I fetishizing gay sexuality in the same way as straight men who are turned on by watching two women kiss? Are they, in any meaningful sense, fetishizing lesbians? (I’m sure they don’t care whether the kissing women are, in fact, lesbians.) Does it make a difference that women who ship M/M care about the feelings and personalities of the men they ship in a way that straight men watching F/F porn generally do not? Would I tell my gay friends that I read and write M/M smut? (The issue has never arisen, but I think if I got drunk enough there are a few I would tell – same as with my female friends, really.)
Anyway, yes, I am familiar with this kind of wank. I gather it is a branch of ‘anti’ culture, often expressed by the same people who oppose kinks and Problematic™ ships, and likes to ostentatiously wave the social justice banner around, just like pretty much every other subculture on Tumblr.