It's not even clear that continuing to allow low margin on these high volatility stsocks would've been good for consumers. The price would've got driven up further, the shorts would go bankrupt, the companies that loaned the shorts the stocks would recover pennies on the dollar, likely forcing them to sell off their position in GME to cover the losses driving the price through the floor, at which point all those RH traders who don't have quick accecss to the market would be left holding worthless stock, wiping out both their initial investment and probably getting margin called.
Edit: Nope, looks like Robinhood "Instant" is now the default, margin account, but still limited to $1000 per account:
https://robinhood.com/us/en/support/articles/robinhood-accou...
I'm assuming you mean the DTCC? This actually isn't true now, as the DTCC have reportedly upped their margin requirements for GME orders to *100%*. That's according to the CEO of WeBull. That's why these clearing houses, and by extension brokers, cannot afford to sell GME stock to retail traders.
This is more or less like the futures market, except futures trades settle at end of day (when CME closes for an hour at 5pm, and next day starts at 6pm lol) and DDTC is the equivalent of CME
Who’s irresponsible here? DDTC for their lax cash requirements? Individual brokers that only keeps the minimum required cash? Futures cash requires 10pct or less, but no futures trader would only keep that much in their account, unless they don’t mind being wiped out and liquidated at end of day settlement (and then deposit more money the next day to trade again). Brokers cannot risk being wiped out at all.