Are there any examples of other skills where the distribution is bi-modal? It would be extremely atypical. I think the default assumption has to be that the curve is the classic bell shape, like most skills, unless there is evidence to the contrary.
More over, I think the point that programming skills can be learned is an important one. In the west we tend to think people have certain innate abilities and weaknesses, like some people are just bad at maths and can't be helped. In some places the assumption is that almost anyone can master almost any skill with enough studying and practice. If someone wants to do programming, or any engineering, to achieve some other goal they can learn to do it well, even if they don't love programming for the sake of programming like some nerds do.