I like your analogy but it didn't quite convince me, and I was trying to work out the best way to explain why, and here it is: How many of the world's buildings were commissioned, and had fantastic architects working not on their own ideas but on the ideas of people with money? Or painters hired to do a portrait, or composers hired to write an opera around a libretto.
Of course, in most of those cases I would assume that the person/s providing the money would have a lot less input into the final product than a non-technical founder would have in a company, so perhaps they're better compared to a VC than a founder?
If the business decisions guy was also bringing money to the table, then that changes the story. But now the important contribution is the money, not the decisions.
I imagine a conversation with Mozart went something like this:
"Mozart, I want a libretto."
"What should be in it?"
"It should be about birds."
"Okay, I'll get on it."
The corresponding conversation in our world would be:
"Jack, I want a piece of software."
"What should it do?"
"It should be like a blog but every post limited to 140 characters."
"Okay, I'll get on it."
It is Mozart and Jack who end up making 99% of the design decisions. What I'm saying that once the guy hiring the creator gets so involved that a good portion of the decisions are his/hers then that's a very inefficient way to compose a piece of music or a piece of software, and you're better off doing the composing yourself. Of course in many cases marketing is more important than the technical side, but this is no different. In a startup with just a couple of people the contribution comes from the guy doing the marketing, not a guy deciding the rough marketing strategy. In a big company the influence reverses because the business decisions have a lot of leverage simply because they affect what a large number of employees are going to do. Simply put, the question you're asking is "Could twitter be done by me getting YC (and later VC) money and then hiring a programmer and a marketer?". The right question is "Why would the YC give the money to me instead of the programmer and the marketer?". Note that a perfectly valid answer for a lot of startups could be "I have connections and experience in the field" (especially for e.g. medical or payments startups), but the answer needs to be something.
Of course, in most of those cases I would assume that the person/s providing the money would have a lot less input into the final product than a non-technical founder would have in a company, so perhaps they're better compared to a VC than a founder?