Spoiler alert: they don't. Wrote a slightly longer rebuttal on Medium: https://medium.com/@sonyaellenmann/cmon-this-is-oversimplify...

In a philosophical sense, it is not helpful to perceive the difference between "ideas" and "execution" as a binary reduction on two sets. Instead, I view it as the idea-execution gradient.

The theoretical limit on an idea-first mindset is 'literally only your idea matters. It doesn't matter how you execute it.' The theoretical limit on an execution-first mindset is 'literally only your execution matters. It doesn't matter what the idea is'. We can represent your stance on this gradient with a rational number coefficient, M. What you believe Matters.

If you have a low M, you are idea-first. If you have a high M, you are execution-first.

Let's assume the existence of a hypothetically Platonic M. By definition, founders of the most successful startups have a Platonic M.

My point was, I believed the Platonic M is currently far lower than what the Valley rhetoric advocates for.

I agree with this comment -- excepting the last sentence -- but it's a far cry from what the Medium article said.

Perhaps my subjective belief of the Valley rhetoric is wrong.