My theory is this: the right has rarely been able to spontaneously mobilize people without a lot of money from rich backers, so they naturally assume that's the only possible explanation for large groups of people mobilizing on the left. It's hard for them to fathom the idea of people independently joining together in solidarity without a top-down infusion of resources and marching orders from an authority figure. They view any kind of organized progressive movement through this lens, which is why Derec still thinks anybody who tweets #BLM is reading from some kind of sinister playbook that gets handed out by Al Sharpton every month, and why whichphilosophy thinks Marxism had anything to do with women not liking the direction of the new administration. These outlandish rationalizations somehow make more sense to them than the existence of a bunch of people with loosely related, overlapping, heterogeneous views making noise for a variety of reasons.
This is actually the best explanation I have heard of the phenomenon.
I agree