[dchapp]

I agree that use of "good" is questionable here. One would think that without the skills mentioned, one wouldn't be a theoretical physicist at all. (Is every person who lacks these skills a "bad theoretical physicist"? Only in a vacuous sense.)

That said, I think we should interpret "how to become a good theoretical physicist" as "how to gain the competencies that are expected of s theoretical physicist."

[Retra]

That's is what he means by good: one with enough competence in the field to do actually useful work. If you manage to do useful work in physics, that work could translate into a Nobel Prize just as easily as any other useful work.

A bad theoretical physicist is one who only understands enough to sound smart to their friends. AKA, a crank.