Dell, too, is healthy – it’s just not achieving its growth targets, arguably because of a series of mis-steps. And I can’t see any reason to think that investing hundreds of millions in building its own completely incompatible operating system would help it.

John’s only argument appears to be “that’s what Apple does, and it succeeds”, which isn’t much of an argument.

And Dell has looked a bit poorly, in the long-term view, for some time now.