Now, start removing everything and see if you can still build something. Remove marketing? Yep, I can still build it. Sales? Yep. Design? Yep. Product Management? Yep.
Coding? Nope. Can't even build it if you don't have that. The other stuff is definitely important, and it definitely makes or breaks successful businesses, but none of it is essential. Coding is a hard requirement when you want to make software, and if you don't have it, or understand it, then all the other stuff is kind of pointless.
The stupid thing is it's not that hard to learn the basics. It just seems "idea guys" want to be lazy and not learn the essential element of the business they want to enter.