This is a problem only if the person is bothered by their lack of "success". For some, being a dilettante may precisely be the life that they want. The problem

This is a problem only if the person is bothered by their lack of "success". For some, being a dilettante may precisely be the life that they want. The problem is that if you are perceived as "smart" people all around you will push you to "succeed" in traditional ways, either because they want a share of the profits of such "success", or because they see someone not doing the boring grind as a moral failure, or out of concern that the dilettante is "throwing away their potential". I'd say that if you are "smart" then it should make your life freer and not more constrained.