[Note: This post is prompted by nothing in particular. I just want to have it on hand so as to save me some typing when the next person cleverly diagnoses the hypocrisy of a Marxist who participates in capitalism.]
The Marxist critique of capitalism is that it is a totalizing system that forces everyone to participate in it. Hence it is not hypocritical for a Marxist to participate in that system while working toward a revolutionary change in the mode of production.
Just the opposite: it would be profoundly hypocritical for a Marxist to presume that they could individually “opt out” of capitalism or preserve themselves from complicity with the exploitation and destruction the capitalist system produces. That would mean buying into the capitalist illusion that everything is ultimately determined by individual choices.
Yes, it is possible to be more or less exploitative, more or less complicit with the very worst — but charging money for Marxist books, for instance, is not hypocritical. If you think it is, then you simply do not understand Marxist theory, full stop.
An und für sich 
It’s not enough for you to validate your own position. You have to polarize it and insist the other possibility of trying to opt out of capitalism is “profoundly hypocritical”. Would it kill you to admit that both positions can be honestly held and logically defended and that the only time we will be able to say for certain which was the correct one is the famous last instance that never comes?
I don’t disagree with your point here at all, but “participate” is not very well-defined. I imagine you’re using it to mean, like, having a job (and a 401k, perhaps) and consuming products and so on, but I have seen people who claim to be anti-capitalist and are investment bankers or foreclosure lawyers, for example. Are those hypocritical forms of participation for Marxists?
Yes, it would in fact kill me.
I think Ethan substituted “participate in” with ‘participate in particular ways’. That one could be hypocritical is a different argument all together.
I’m largely in agreement with you, Adam, which leads me then to ask: who are these people with whom you’re disagreeing? I’d like to see who the people are who’ve publicly made an argument that Marxists can or should in some way not participate in the forms of economic labor, transaction, and enterprise associated with capitalism as a historical-material formation.
It’s a very common “gotcha” criticism online. Watch for it and you’ll see it.
Hypocrisy is not even a thing. Who cares what people do, capitalism doesn’t give us the freedom to be ‘who we are’. I see no problem with being an investment banker and wanting international proletarian revolution. Communism isn’t Jesus returning to judge the living and the dead.
Usually in the form of “Isn’t it ironic you are criticizing capitalism while using your iPhone?”
More serious response to Mark Wallace: I’m not just trying to be a dick. For a Marxist to adopt capitalist individualism, as though Marxism is just one lifestyle brand among others, is actually hypocritical in my opinion.
Ethan: Note that I say, “Yes, it is possible to be more or less exploitative, more or less complicit with the very worst…” That would cover your Marxist investment bankers.
Pienaar, It would be hard to take that investment banker’s desire seriously if he wasn’t doing anything. Engels was an outright capitalist industrialist (by inheritance), but he used his fortune to bankroll Marx’s writing career.
A popular tweet suggesting a lot of people are fed up with similar gotchas: https://twitter.com/mammothfactory/status/719009193894768640
Cheers though to one kind of opt-outers — not the smart shoppers, but the people who construct alternatives to capitalism as collective projects. Prefigurative politics. The Engler bros are good on this.