>
There's nothing stopping them from opening an account with Charles Schwab(I've gone through Charles Schwab's account signup) Charles Schwab, for example, has minimum amounts for opening an account; IIRC, it's $5k. There's also ~200 pages of legal agreements to wade through. (But everyone just blindly accepts those, right? So that "doesn't count" /s) It also has tax implications.
It's also not a guaranteed thing that these accounts will make money, and I wouldn't be surprised if that uncertainty affects people's decisions.