Why did Bitcoin fall the first time, from $20,000 at the end of 2017, to $3,500 by the end of 2018?
Basically because of miner's fees. Transacting in Bitcoin wasn't profitable, because miners got together and raised their fees so high that it wasn't worth trading Bitcoin.
So, it was the miners' fault that Bitcoin fell.
Miners aren't the only ones enforcing the 4MB block weight limit. The entire network of full nodes is. And it's limited block space that drives fees up when there is strong demand for transactions.
So it's
all Bitcoin users -- or at least node operators -- who are to blame, at least according to your theory.
Here's the thing, though. Why do you think it was high fees that caused price to fall? Previous bubbles burst the exact same way.