The flaw in your reasoning is you present different areas and don't consider overlap. The way you explain it, you make it sound like a hacker / coder is a beast more constrained by his class than a twelfth level paladin.

A successful startup will have members who individually fill many roles with diverse skillsets. For a web startup I fully believe the most important factor is being able to take whatever vision you have and form it into reality.

If you don't understand the customer base you won't do so well. If you can't build your product you won't do anything at all.