What exactly is tangible about this advice? The only thing tangible about it is that everyone is going to be trying to analyze everyone else to see if the fit into the mystical buckets of A players versus B players.

Seth Godin sometimes has interesting insights but this type of stuff is just selling self help advice that leads to nowhere. Just do what your interested in and think your good at - stop trying to put yourself and others into meaningless buckets, people are people, not A vs Bs.