“Like, hey man, if you’re complaining that the system is totally unfair and forces most people powerlessly into a narrow set of compromised choices, why are you making one of those choices?”
When I worked with Tom Morello he used to get it all the time too. It’s a bogus argument. There’s no requirement that one leave the system they are in prior to expressing fundamental doubts about that system.
I could often be described as an “anti-capitalist”, in the sense that I advocate for newer systems of organization of labor and productive resources, but I recognize that I do not live in a post-capitalist society. I still need to participate in the capitalist world to participate in society and acquire the resources I need to survive and thrive. An anti-capitalist will often need to participate in capitalism. They can still work to build an alternative system even as they participate in this one. The process of promoting or designing a new system could benefit greatly from some capitalist wealth to reach others who may want to exit.
Being against capitalism doesn't mean total aversion to commerce or the capital it generates., but opposition to market forces being the dominant ideology. Even hard core communists I know don't mind if someone is a bit rich (eg worth a few million), but are opposed to the vast concentrations of capital in limited liability firms, and want industrial infrastructure to be publicly owned.
Capitalism was never alive. We live in a state capitalist system. A free market capitalism is a fiction, and where it was almost a reality ( Somalia ), it never ended well.