Exactly!! This is very true
A Startup has nothing to do with a 'node.js/RoR/GoOnSkis/etc' stack or computes. The association is statistical rather than structural.
The business comes first.
Of course programming helps and saves pain. But my money is on the business knowledge first.
Yes, the 'computer people' like to bash the business people, and it is often true that sometimes they have bad ideas or act like they know the business when they don't. This is like the tech specialists thinking a product will sell only based on its tech specs.