Bitcoin isn't their Plan B. They would never introduce something they can't control.
Marxism, Communism, and Socialism have failed repeatedly, and have always hurt the poor and lowered the quality of life for everyone. But despite repeated failures, they still succeed in spreading the same failed ideas on the internet.
How does Socialism hurt the poor or lower the quality of life for everyone? And why do you not include Democratic capitalism? Surely that has failed too?