There's a broad spectrum of public companies obviously, but it's hard to see $AAPL as speculative in the same sense that people call penny stocks or cryptocurrencies speculative (i.e. much, much more risk involved in the latter two). Investing in large cap equities isn't the stupidest thing you could be doing as a new investor - that award would certainly go to buying derivatives.
And indeed if I have criticism of RH it's that they're trying to appeal to all investor types at the same time, new and experienced alike. It's easy to see how new investors can get confused when RH offers the ability to sign up for cryptocurrency trading and options trading, two things new investors obviously should not be doing (though admittedly there's obviously a questionnaire involved before you can be approved for options trading, not sure about cryptocurrencies).
More than 90% of my investments go into index funds and 10% into individual stocks, but if hindsight was 20/20 it would be 100% into my individual stocks and I’d be retired on my own private island today.
But yes most people are better off buying index funds. That's where most of my money goes.
I don't think Robinhood is terrible. I just think someone who doesn't know what they're doing would be better off starting with Betterment or Acorns, which are just as user friendly as Robinhood.