OnlyFans Star Ari Kytsya just spoke to a class at Harvard about her adult entertainment career and, of course, got some backlash ... and she's ready to give haters an education.

Here's the deal ... Ari was invited to speak at the prestigious university about taboo businesses ... topics she obviously is well-versed in, being a massive OF star. And yet, she still got flak from those who said her presence on campus was a joke.

Watch the clip ... Ari tells us, those bent out of shape likely have zero clue what she was even invited there to speak about ... and being so close-minded comes from a stigma she and some of her colleagues are hoping to change.

The adult-entertainment star says she wants to start making sexual content that is not dominated by outdated, male chauvinism ... and even show that porn can have "consent" dialogue so viewers know it's OK and normal to communicate with their partner.

Bottom line ... Ari says snobs giving her grief can go crack a book.