Casinos LITERALLY do this though, with segregated/exclusive higher stakes games. You only get to play the ultra high stakes poker if you set it up yourself or get invited
No one holding GME is having their holdings seized.
No one holding GME is prevented from selling (by Robinhood; periodic circuit breakers do inject halts for everyone during periods of high volatility/price movement, which are rules set in place before [this] play began)
No one is prevented from opening an account at the many dozen other brokerages who are happy to transact in GME.
And the simple fact that millions of people on RH are locked out of buying totally fucks the people holding the stock. "You can sell but not buy"?
Who is buying? The institutions.
Do not attempt to justify this.