I have seen a lot of people who think they have awesome ideas for a startup, but they do not know how to code. The lack of coding skills actually does not let them see the actual complexity and use of their idea and hence it's feasibility.
Also having coding skills, really gives you the power to innovate, its quite common that the idea can change drastically over the course of development, and that happens only because when you start coding you can see the merits and demerits of your ideas. You understand where you can improve and what you drop.