I completely disagree, and I'd say the opposite. If someone has the motivation be self-taught, then they will have the motivation to try difficult things. Though I would agree that you can't really be well self-taught unless you really have the determination for it.
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.
I've seen another article recently that claimed that self taught people will only attempt "easy" things. I just thought that was derogatory, because other than being self-taught, I didn't "resemble that remark" in any other ways; he painted a picture of someone doing some hypothetical "bad PHP website".