This is one of those things that's yet another example of something being treated academicaly which does not need to be treated that way. And of making something much more complex than needed. In real life, in actual practice, any working software engineer or heck even open source hobbyist programmer can tell you that talent and ability and productivity vary significantly between individuals. And this isn't just true among programmers, it's true in other areas/fields as well. This is not controversial, or at least it shouldn't be. And yes, some individuals are clearly 10x or 20x or whatever better than others -- for whatever reason, and the reason(s) doesn't matter too much honestly. It just is.