A broker is nit your friend who refuses to buy junk food for you because he suspects you’ll be sick.

A broker is yiur fiduciary/agent; their discretion at refusing your order should be limited to well defined circumstances, and I would be surprised if this is one of them.

(I would not be surprised if the EULA lets them do what they want, but I would be surprised if it would actually be found legal in court —- though it will likely take ages to test because it likely contains a binding arbitration clause)

It's not what I was trying to say, of course they're not your friend, I'm not that naive. But on the other hand if many of their users go bankrupt because of poor trades that could backfire against Robinhood themselves, directly or indirectly (for instance by motivating new regulations).

Sorry, but no. Concern for the little people isn't even slightly indicated by Robinhood's actions.

WSB have been yoloing their trades since forever.

This is some anticompetitive bullshit, plain and simple.

That doesn't make any sense because they still allowed them to sell, realizing a loss. Why not stop buying and selling?

This right here. Only allowing sells appears to be blatantly anti-retail investor, intended to help drive down prices for those with short positions needing to be closed.

Exactly. How are retail investors supposed to benefit if they are forced to wait until the stock they just bought tanks? If anything that's a direct attack at the value of your portfolio.

Try calling up your local Charles Schwab office to ask them if they'll stop you from making bad trades. While you're there, also see if they'll help you get your money back if you lose money on bad trades.