The $64 question: Reform, subversion or revolution? The answer: yes.
Even the most hard-core no-compromises revolutionary must admit that even the most dramatic revolution in state power will still inherit both the physical means of production as well as the psychological, social/sociological and political superstructure of a capitalist state. Capitalism has been shaping people's values and ethics for hundreds of years, and ruling class/working class politics have been doing so for thousands — perhaps tens of thousands — of years. Not even the most brutal ideological repression can erase this millennial influence in a generation.
For this reason, every communist thinker and statesman, from Lenin to Mao, understands that a transition from capitalism to communism (i.e. the liberation of all humanity from all forms of exploitation and oppression) requires a transitional period of socialism. And socialism is differentiated from communism precisely in that socialism includes some capitalist features, including class distinctions (you can't have a dictatorship of the proletariat without having a proletariat distinct from the bourgeois), private property and private enterprise, money, and differences in standards of living. Even Marx said that, "From each according to his ability, to each according to his need," is the goal of communism, not the strategy of achieving it.
Measured against the ideal of real communism, any practically possible revolution must be incomplete, and therefore in an important sense will be a reform.
In addition, both reformism (and economism) and subversion can be used to to good effect as strategies and tactics for creating a revolution. I'll talk about this aspect in a future post.