From what I seen, I wouldn't define it as a "Left Wing" thing.
There are those who find it offensive simply because it has been used offensively against them, and I'm talking about racial terms now, not ideologies.
Go to Pinterest and search "Moors," and eventually that will lead to Afro-centrists, who, as the name would indicate, are just as racist and revisonist as their Euro-centrist counterparts. According to them, Moors weren't Moroccan, they were sub-Saharan Africans, and thus so are Spaniards. They invented everything and introduced it to Europe via Spain - even things like running water, thousands of years after Rome did. The more memes and pics you look at there, the more bizarre they get. Black supremacy easily rivals White supremacy for being way out there. They even claim that Native Americans weren't the Native Americans, but Africans were. All them pics from way back were faked to keep us from the truth, I kid you not, that's what those posts claim.
Anyways, I assure you, that their perspective is not something coming out of some left wing thing...
I can't even chance looking at legit stuff concerning Africans or 'Black' Americans over there because all too soon it leads into this stuff, and then it'll be in my feed for days, and somewhere between laughing and clawing my eyes out, well, that's not exactly good for my general well-being and and whatever tether to sanity I might still have.
I'm rambling,,,