And for some it worked out pretty badly. Hungarians rebeled against communism, but that rebellion was put down brutally.

You are correct that towards the end of the Soviet Union many of the client states and Russia itself had popular uprisings which succeeded, but that that point the Communist Government was already failing.

My point is not that no popular uprising has ever worked or that outside pressure can not force the end of some regime, but that telling people that they need to take up arms against their government is an insane proposition.