No one remembers that most short positions are actually held by retail investors. I myself regularly take short positions.
The reason trading was stopped is that if a stock price suddenly gaps then the retail investors can lose more money than they have in their accounts. Then the brokerage or their clearing firm have to take the losses. They are not willing to do so, so they stop allowing trading. The brokerages are not somehow colluding to make hedge funds money, they are just trying to make sure that they do not lose money themselves.
The reason trading was stopped is that if a stock price suddenly gaps then the retail investors can lose more money than they have in their accounts. Then the brokerage or their clearing firm have to take the losses. They are not willing to do so, so they stop allowing trading. The brokerages are not somehow colluding to make hedge funds money, they are just trying to make sure that they do not lose money themselves.