What would he say to the idea of selling Apple hardware without tying it to an OS?

In other words, you can buy the great Apple form factor and design, but you don't have to deal with the restrictions of the OS. You could install your own OS.

Obviously this would initially only target hackers. NetBSD can run on some Apple hardware. And there is all the Hackintosh work to build on. Eventually there would be more free OS offerings to install after giving the hacker community some time to adjust to the newfound freedom.

Apple could even sell OSX and iOS separately.

There is a lot of value just in the Apple hardware. Even without the Apple OS offerings. Apple is primarily a hardware company.