More like regular beans and magic water.

Or, regular beans and regular water, but a "magic" combination of legume-growing and real estate insight.

Stop trying to ruin the magic!

Are you, by any chance, an expert in fluid dynamics?

Sorry, no. I'm a gardener, so I'm more about the soil...

Why do you ask?

He just needs a cfd expert, he's already got water

As long as the roots are not severed, all is well. And all will be well in the garden.

The field of fluid dynamics is enormous to the point that experts from its different branches may not understand each other (how much resemblance bear under the hood the modeling of weather, internal combustion engines, oil wells).

To continue along the same analogy: the entrepreneur doesn't need to know about water, they just need to know what a good beanstalk looks like.

That's my problem with "I'm the magic water" software developers. I can work out how to pay them, but I can't work out how to make them understand users well enough to make good business decisions about a consumer-focused company.

(Note: I'm actually a developer. And I see that you understand the counterpoint as well, as shown by your last line.)

I don't agree with your first line. If a manager knows what a good product looks like but not how to make it, he cannot manage its development. The same is trivially true of business things as well. We all know that good sales are high sales with low numbers of customer complaints. How does one manage a salesforce to achieve this?

If the salespeople say that the customers don't want what we sell, are the product managers to blame? Or are the salespeople not very good at their jobs and clinging to the false objections raised by prospective customers?

A sales manager must a decent understanding of sales to manage sales. A development manager must have a decent understanding of development to manage development.

An entrepreneur in a software-centric company had better have a decent understanding of several different things to succeed. It is not enough to say, "I know good software when I see it," IMO.

It was a tongue-in-cheek way of pointing out that an entrepreneur needs to be able to wear all hats. Business students like to think that it's 95% business and 5% development. Developers like to think that it's 95% developers and 5% business. Obviously neither is right.