Marx might have recommended revolutions in 1850. By 1871, he advised the Paris Commune not to do it and try to build a Republic together with everyone else.
Revolutions ultimately are not the main point of communism, it's fundamentally about material relations, economics
. Unfortunately, most people just care about the politics and ignore the economics -- present day Marxists even take neoliberal theories of value rather than the labour theory of value. They don't realise that is the entire basis of Marxism -- production of goods based on profit results in more and more machinery, technology (constant capital), which reduces the need for human labour (variable capital) until labour is minimal/zero.
Now, whether this is true or not is a different matter, but really, it is not very different from what J S Mill said, and the dreams of a lot of techno-utopians. Techno-utopians are already kind of implementing "lite" communism with stuff like the sharing economy, open source software etc. With open source software, one programmer can write a piece of code that thousands after him can build on and use for free, that's pretty much constant capital.
I don't think utilitarian/marginal economics has much to counter this. They merely conflate value and price. I find the liberal idea that profits are the "wages of abstinence" milquetoast and retarded. The wages of abstinence are the wages of the ascetic, not of the capitalist. There certainly is a risk component to it, but then there are plenty of risk-taking entrepreneurs who end up with nothing.
I think the biggest criticism of communism (and really, most other forms of political economy which emerged in the industrial age) is not considering the inputs of nature, and only looking at mankind's internal relations.
For example, w.r.t to the labour theory of value, Ricardo discovered this major oversight near the end of his life. He carried out a correspondence with Malthus in which Malthus challenged him on stuff like whether 50 oak trees costing 20 GBP each contained as much labour as a 1000 GBP block of stone. He tried to address some of the issues in the third edition of his Principles, but couldn't fully resolve them. He went on a different thread, talking about the "labour profile" of production, which I think his later successors (including the Ricardian Socialists, which Marx certainly learned from, and J S Mill) took up, but I think (my own opinion) all of them pretty much ignored nature's inputs in value.