Autonomists disagree with Marxists, generally speaking, in that they don't see socialism (or whatever you'd call an egalitarian democracy) as immanent within capitalism. Hence the need, one assumes, to create autonomous space outside of capitalism. If that is the case then autonomists cannot help but agree with Tory MP Louise Mensch's contention; you cannot criticise capitalism from within it.
But, if you do agree, you're missing one of the most basic philosophical points assumed (assumed but not often understood). It is generally given that to critique something you have to know it. The surest form of knowledge comes from a combination of theory and practice, hence Engels's conclusion that the working class, which both thinks and does, is the inheritor of German classical philosophy.
You cannot criticise capitalism, practically, theoretically or practically/theoretically without being within it. So enjoy your coffee.