You've just described a two magnitude spread between an incompetent programmer and a "rockstar" (I hate that term), with the average being a 1x programmer. I tend to believe that's true because I've seen a few 10x programmers (and I think I've had days where I have been one), but I've definitely seen 1/10x programmers. This sounds about right.
Eh the thing of it is, everyone can have 10x days, as a developer's output variability is high, the trick is to hit that consistently, and to do that you basically have to have 100x days at least once in a while.
