Every human ability has a natural distribution of what for a better word we can call "talent". This is as true of running or tennis as it is of coding. To claim otherwise is to tell people who aren't naturally very good at tennis that they are moral failures for not working hard enough at it, which is insulting and demeaning as well as false.

Furthermore, there is evidence that the ability to code is non-linearly dependent on some fairly uniformly distributed basic abilities. The bimodal mark distribution of first year software courses is evidence of this. It is trivial to reproduce it using the assumption that the underlying skill-set is uniformly distributed, but there is a threshold of ability below which coding becomes very hard: http://www.tjradcliffe.com/?p=1471

There is a very simple way to disprove this hypothesis: find a way to teach coding that will get rid of the bimodal distribution of marks, which has been vigorously attacked by educators for decades without progress. The things we have learned in that time are:

1) It doesn't matter how passionate the teacher is about believing that "everyone can learn to code"

2) It doesn't matter what language is used

3) It is very hard to predict who will be good and who will be bad.

Because of this, there are three reasons we know cannot be the source of the problem: the attitude of the teachers, the langauge used, or the number of years experience prior to university. If any of those were the cause the extensive research on this issue would have revealed them in the 80's.

I'm prefectly willing to believe that most people can be taught to code, and if I can be shown evidence of a teaching method that gets rid of the bimodal distribution I'll happily abandon the barrier-to-entry model I've proposed in the link above, but until then, it can't be called anything less than a plausible hypothesis. Certainly not a "myth".