I think much of the problem is that to be good at stock picking and trading, you need to spend a lot of time on it. Most people don't have that much time. Buffett and Munger do this for a living, after all, and they've been doing it for many decades.
And of course a lot of people just aren't any good at it. That isn't shaming; nobody's good at everything.
And at the bottom of the barrel we have the plungers who eternally hope a randomly chosen triple zip penny stock will make them rich rich rich.