I don't think anyone can be a coder. Believe it or not some people just don't have the mental capacity to grasp the concepts needed in coding. Most people could learn how to code and be quite fluent in programming, like learning to speak spanish or any other language. Some people pick it up quicker than others but most people are able to get it eventually. On the other hand if you're a creative person it's a big plus in programming too not only design. If you think of some idea that is totally out of this world you have just gotten past one of the biggest steps in creating a new application... the idea. Creativity can also help you strive to learn new techniques and shortcuts in your apps instead of making everything straight forward.

Thats just my two cents.