Part of that comes down to sheer numbers, but I feel there’s cultural differences that go into it too. Having lived in Japan I found that relative to the US, the average person is more likely to be decent at drawing/doodling or have interest in other forms of art.
I don’t have any special insight to why that’s true (if my experience is representative of reality — n=1 and all), but my hunch is that it might come down to an overall less self-defeating and more supportive attitude towards self-expression through art… in the US it’s common for people to completely dismiss the possibility that they could ever create anything of value, citing things like lack of talent. There’s also a consistent undercurrent of a disparaging attitude towards artists which also doesn’t help.
With those cultural differences, it’s easy to see why one group could end up with a higher percentage of creators than the other.