[WS:] The crashes come and go, and people start playing the same game over again. You can take a description of the 1929 crash, change the date, and it will fit the 2008 crash. In other words, you have one generation getting totally fucked up by capitalism and getting wary of it, then a new generation coming in thinking that this time it will be different and doing the exact same thing over again. Greed trumps reason - that is the "beauty" of capitalism. And this is also why well known scams like three card monte, get rich quickly, and ponzi schemes always work.
This whole thing may be unsustainable from a "systemic" point of view, but we are dealing with people here not with impersonal systems.
A perpetual motion machine will not work as a system for very long, period. But if you convince enough people to put their faith money and energy into it, they will try to restart it each time it stops thinking it was just a temporary glitch and the next time will be different. And you only need to coax a small number of them with rewards, the rest will follow like sheep. Same with casino gambling and capitalism.
So while Marx was right about the systemic unsustainability of capitalist growth, he was wrong about this being a cause of its downfall. He thought people are rational and learn from experience. Some perhaps do, but most don't. They will keep doing the same thing over and over again, expecting different results.
Wojtek