All of this depends on the person. Somebody who is self-taught because they want a job in programming is going to tackle easy problems. For the same reason, and I know I'm speaking to the wrong crowd to say this, someone who is just in a hurry to slap an application together so that they can sell it will also not tackle anything really hard.

Somebody who has a problem that isn't solved by any current software will, by definition, tackle something harder than someone who is just trying to make money.