Marx vs Che

Both are true, but Marx's quote references revolution as a social and historical phenomenon and Che's quote talks about an individual's approach to revolution.

To put it another way, capitalists do indeed dig their own grave, but we workers need to push them in and bury the casket.

“What is scientific socialism without the working-class movement? — A compass which, if left unused, will only grow rusty and then will have to be thrown overboard.

What is the working-class movement without socialism?—A ship without a compass which will reach the other shore in any case, but would reach it much sooner and with less danger if it had a compass.

Combine the two and you will get a splendid vessel, which will speed straight towards the other shore and reach its haven unharmed.”

There are no contradiction here. Marx only states that capitalism will create the material condition for a revolution, he does not imply that it will magically happen.

Heaven and Earth change, but it is Man's will to seize the opportunity.

The fall is inevitable because it creates revolutionaries. But it’s up to the revolutionaries to take action.

they're not necessarily opposing viewpoints. revolution can be inevitable whilst still requiring a human action to start it

100 years after the communist manifesto, it was clear the revolution was like an olive tree, it needs some shaking to drop the olives.

I think both are true. People do have to put on work, but that people will do that is inevitable

The idea that the proletarian revolution was just going to happen was Kautsky, attributing revisionism to Marx is a take

Not trying to read too much into this if it's a joke, etc.

But

Marx was stating as an absolute statement of what he viewed as fact (and seems to be correct over a long enough timeline) that capitalism will fail due to contradictions

The Che quote is the less philosophical, more "in the shit" statement. Much like Lenin before him, these guys understood that the contradictions of capitalism lead inevitably, as Marx was getting at, to failures and collapses and it's at those moments that revolutionaries spring up and rile their base of support within the labor force of the country. Until that moment of crisis things were bad, but tolerable. During the crisis, conditions are intolerable and people are willing to do anything, including overthrowing the government/capitalist class and possibly dying for that cause. Because the alternative is death anyway. Or a living death.

On a side note, this is why there will never be (for any foreseeable future) a socialist revolution in the US. 1) material conditions are broadly "good" (although they are worsening) 2) there is effectively no leftist political movement in the US. There are a few thousand people who are genuinely anti-capitalist, anti-imperialist and want a revolution, but that might as well be zero in a country this size. Not anything new or crazy to point out that as people's conditions worsen further they will turn towards more and more radical leftist ideas or right wing ideas. Considering the racist undercurrents of the US and lack of any desire for any international cooperation amongst workers mixed with the (unfortunately extremely effective) FBI/CIA ops against US leftists in the past, there's only really one path that we're likely to head down...

I think it is both. People are naturally the most revolutionary in times of crisis and struggle. It is the conditions which are created by the capitalist system that make the people feel that the system they live under is untenable, especially with rapid changes in conditions as experienced during financial crises. Many within the bourgeoise study the instability of capitalism in order to protect their capital or to profit from it.

Yeah, but they're both dead now, so why should we listen to anything either of them said?