They can port Xcode to iPad, offload compilation to the cloud and you don't need Mac anymore.
I think the UX of this idea will be bad, just like the UX of the Mac has declined, both resulting in lower developer support for the platform over time.
Just a theory. Not sure why Cook wants to test it.
The developers that actually have bought Apple computers to work on Swift and Objective-C, instead of a pretty UNIX to develop GNU/Linux applications.
Money helps here. People were writing software for Windows even during the darkest days of Vista. On a mac or linux, if possible.
Sounds like an apple problem, not a problem of us power users who moved to something better.
My point is Apple, and Cook, should be looking at this as an Apple problem.
My question is the question they should be asking themselves.