The original version of the "10x" idea didn't require the productivity distribution to be bimodal - it could be a bell curve or skewed bell curve with high variance. I think it's contextual as well - if you're working on a project that's just at the edge of your present abilities, your productivity is going to be pretty marginal compared to someone who's done it before and has strong aptitude at it.
I think it's silly to simply sort programmers into two buckets.
It does make a lot of sense though to try to attract and retain good programmers though - having a programmer who's at the 75th percentile of productivity instead of the 50th percentile is going to give you a big boost in productivity if productivity is high variance. It also makes sense to try to match programmers to projects that they have good aptitude and motivation for.
I think it's silly to simply sort programmers into two buckets.
It does make a lot of sense though to try to attract and retain good programmers though - having a programmer who's at the 75th percentile of productivity instead of the 50th percentile is going to give you a big boost in productivity if productivity is high variance. It also makes sense to try to match programmers to projects that they have good aptitude and motivation for.