How does that theory explain,
* So many people using the same nonsense talking points at the same time. Did they coincidentally make up the same lies? With no anchor in objective reality, why would they converge on the same talking points?
* The sophistication of the talking points: IME they are often very well-crafted - seemingly professionally crafted - public communication. They effectively frame the debate, shift attention (often attacking the messenger), use powerful emotional impact to bypass reasoned discussion, and acheive the main goal of disinformation - paralyze discussion. Did people invest the time and effort to craft these talking points on their own, and do it so effectively?
It's not exclusively random people doing random stuff, but it also doesn't require a large, well funded, conspiracy. People see a fake poll that confirms their preferences and then proceed to propagate the message.