That's not the answer, it's the mechanism of that violence.
> unless you somehow deny that communists were equally dedicated to subverting and overthrowing the west.
I will absolutely deny that. Note the number of capitalist governments coup'd by communists. Note the number of invasions and constant wars of The West. Look at Vietnam. Western involvement was long-reaching, direct, violent, and generally within other countries fighting grassroots revolutions / civil wars or throwing off colonial it imperial influence.
When attempting to find similar situations started by communist countries, we find important differences. Dragged into conflicts on their borders. Literally fighting a genocide directed at themselves. Long-standing territorial disputes on their borders.
> I disagree that this is a valid generalization
Feudal backwaters subject to regular famines became superpowers that eliminated homelessness and hunger. And the fall of those systems corresponded to drops in QoL over and over and over again.
What other tests would you want?
> This is because the centrally planned economy depleted vast amounts of capital in their desperate struggle to keep the economy moving and competitive with the west.
Capital is just stuff or money tradeable for stuff. The stuff didn't go away after color revolutions. But public programs were absolutely privatized or abolished by liberal capitalist governments in moves aligned with their ideologies - ideologies you can find throughout this site, in fact.
> Cynically I could offer the same answer a communist would offer when asked why people weren't permitted to own factories in the Soviet Union: because that would put "the wrong people" in charge of the means of production.
Ah, but in that case there's a consistent ideological position: bourgeois democracy and ownership must be curtailed because otherwise it will grow and eat you and those you love. According to liberal democracy, you're supposed to be able to seek and form a representative government in a multi-party setting - yet they restrict those parties to force bourgeois options to be the only ones available.
The supposedly core ideals of The West clearly bow to capital when push comes to shove and one should question the propaganda that it's these ideals that won or were even the actual goal.
> Less cynically, its not clear how a centrally planned economy would know how to correctly allocate resources, so there's no reason to return to the central planning model in the absence of a solution to the problems that caused it to fail in the first place.
But the vast majority of several countries want that return, with support increasing with age - the people who actually lived under communist party rule. They are prevented from doing so by their political systems. It cannot be voted in. Democracy clearly doesn't mean that much to The West, right?