When it comes to Rothko, yeah, you'd have to have a grasp of aesthetics to get what he's driving at. I don't consider him a circle jerk artist though. I think he made his art sincerely and went to significant effort to leave the interpretation in the viewer's hand. In the end, he put colours together to illicit an emotional response. The test of his success is in the hand of the viewer having or not gaving an emotional response to the colours he blocked out. When I think of what I call circle jerk art, I think of people making art for their own inner circle and sniggering cynically when someone comes up with an interpretation that doesn't match what they believe to be "correct."
Yes, for Rothko it takes Aesthetic training to get to the point, but what if I told you that his paintings pose the simple question "what emotional response do you have these colours?" and that for each viewer their answer to that question is correct for them? What most artists across many genres do is show their audience a depiction of human experience to ellicit an emotional response, in a predominantly passive state and if that's what you want out of you experience with art, then yes, don't look to Rothko. there's nothing wrong with that - it's the most successful type of art. In an unconventional way, his paintings don't tell you anything. There's nothing to passively look at and "get," but rather an introspective question to ask yourself. Yes, anyone of us can paint a couple of intense blocks of colour on a canvass. Art isn't just about the technical skill of it's creator. It's much more importantly about the human interaction with the work. imagine asking different people of different ages and experiences "what does this combination of colours make you feel?" and how diverse their responses would be.