I keep wanting to form some kind of housing cooperative for people seeking refuge from abusive situations, seeing as how there's currently fuck-all meaningful resources for adult survivors of childhood abuse. I know that despite this being completely nonviolent, legal, voluntary, and well-intentioned operation, that most people won't care or will actively support when some extremists decide to infiltrate and sabotage that effort. Manufactured consent and all. Why does nobody else do things like this? What has prevented the vast majority of other American leftists from simply crowdfunding their own communes, leaving the larger economy, and building their own means of production so that they aren't dependent on the rest of the world for permission to build systems of mutual aid?
A vanguard party has failed many times, especially in the imperial core, where the capitalists in power have been absolutely running circles around democratic-centralist orgs for 80 years.
There's a big difference between "has not worked before" and "cannot work". You cannot make a universal argument based on critically limited empirical evidence.
The other thing about the vanguard party approach is that it demands proletarians to dedicate their lives to something that there's no guarantee they'll see the payoff from. It's the riskiest investment, with a low expected value. With the communization strategy, you erode the territory and reach of capitalism, and while there's still a big question of how to tie the whole movement together as a revolutionary force, this is a challenge rather than an impossibility.
I don't agree that "such activity [building communes] isn't building for the revolution". In fact I think that revolutions don't just happen because of "heightened contradictions", they happen because there are social networks in place and resources and capacities built up to make the push when an opportunity presents itself.