Retrospectively ascribing success to character traits that we favour is subjective to the point of meaninglessness.

Earnestness, like any other trait or 'virtue' is not innate or absolute. Everyone has the capacity to exhibit this trait or be seen to exhibit it, when refracted through the non-objective lens of someone else's bias and perception. For example, a politician for partyX is seen to be an earnest 'straight man' who cares deeply by his supporters, while supporters of partyY view him as a reckless oaf.

To promote the use of personality traits as a predictor of success is naive at best.

Years of picking through the pieces of other developers loosely documented homespun apps made me appreciate the value in a framework - even a dead or dying one. As a rule of thumb, if I'm developing a pet personal project, then I'll write it myself, if its work then I'll consider a framework, depending on the scope of a given project. In the real world of commercial web applications your project will very likely be touched by many other developers over time. Many of these developers may have a relatively fleeting engagement - i.e addressing one bug or adding one feature.I prefer not to force these developers to read the entirety of my code to do their job.