That's right. For me the new idea in this post is that after you realize that "ideas are cheap", you can continue on to see that "execution is cheap". What's not cheap is money, which you use to polish, scale up, and market whatever you're building.
With modern web startups, money probably matters less, and execution, more, than in domains where you manufacture and distribute physical objects.
I do feel that "access to capital" is the thing that makes or breaks most. I think this is a good part of the OP's opinion.