That's because they don't. The entire application and order flow seem designed to limit the amount of information given to the actual user, in order to make them more confident in the decision. More confident users trade more stock.
I guess you could argue that "a brokerage makes more money the more stocks are traded, so they are doing the best of the brokerages", but would personally argue that a brokerage should have a responsibility to at least partially work in the best interest of their clients.
Out of curiousity I went through their option buying flow the other day (100% expecting to lose that money); it felt more like buying a lottery ticket than a financial investment.
I feel gross agreeing with Robinhood here, but it doesn't really sound like they were in a position to not take the action they did (this time).