From understanding the issue is that RH didn't have enough collateral to execute buys. If they restricted sell on RH in the name of symmetry, but other broker with no collateral issue would still allow buy and sell the stock would remain volatile. In this case, not being able to buy is a nuisance, but won't make you loose money directly. Not being able to cash out in the event of a steep decline on the other is directly and highly prejudicial.

I understand that restricting buys affect the price for those who already bought in, but at least they can still cash out..