Maybe I'm missing something, but isn't the answer to simply have more collateral? Given that RH was able to raise emergency funds around this time it seems really likely that they could have been better capitalized before the turbulence started, and gotten the money on better terms than an emergency deal.
They probably didn't do this because they underestimated the need for it (poor risk models), or simply didn't want to pay the extra cost.
I'm not sure how you got the impression that the parent comment was laying the blame on the user. I interpreted it as excusing the behavior of robinhood. Blame isn't a zero sum game, it's possible to argue that robinhood is less blameworthy without saying that the retail traders are to blame.
>I'd lay the blame with the company that had such poor risk controls that they allowed this to happen in the first place.
What risk controls? As per the parent comment, it's an issue with settlement/collateral requirements, and robinhood not being prepared to satisfy them in light of a stock going 10x in a short period of time. I'm not sure how "risk controls" would have helped.