For that to fit occam's razor I think you need to demonstrate that communist societies actually suffer a higher rate of failure than any other -ism. Most nation states fail. You might even be right to say that most of them fail in short order. The French alone have been through 5 republics in the last couple of centuries.
The simplest explanation, imo, is that power accretes in all civilizations, perhaps moreso in ones that face internal strife or hardship, and that power structures eventually collapse. Regardless of economic or political system.
And from another angle, if a capitalist society fails, is the most likely explanation also the ideology itself? And if both ideologies are to blame for their failure, what's left?
In France, the third republic began with the fall of Napoleon and ended with WWII. The fourth republic was ended by a perfectly peaceful and democratic constitutional reform and that brings us to the fifth. If that's your benchmark for a failing capitalist state, then yes, those fail all the time.
The simplest explanation, imo, is that power accretes in all civilizations, perhaps moreso in ones that face internal strife or hardship, and that power structures eventually collapse. Regardless of economic or political system.
And from another angle, if a capitalist society fails, is the most likely explanation also the ideology itself? And if both ideologies are to blame for their failure, what's left?