If you want to get started learning about it, I recommend looking up Richard Wolff
I don't believe that capitalism is a nebulous concept because I am not informed about it. I believe it is a nebulous concept because I have actually witnessed people in arguments using it to mean different things. Some people consider capitalism as simply a rhetorical foil to Marxism. Some people consider capitalism an economy that while capital is private, the economy may be mercantilist. Others insist that free trade is part and parcel of capitalism. Etc., etc. That's all I meant.
And there's a (not small) difference between bad faith and sarcasm. And tossing around Dunning-Krueger after one extremely shallow interaction is the height of irony.
Your original comment was aggressive but I admit quoting Dunning Kruger, while not misplaced, was also aggressive and escalatory.