The point is that that market is tiny compared to the people that buy iPhones. I also think Apple is doing good things on turning the iPad into a general purpose computing device. For my use cases (ssh somewhere to do work), it is way easier to manage than a laptop, and smaller. I imagine that as the product improves more people are going to make the jump, leaving MacOS in a weird place. (I switched from a Surface Pro 4 to an iPad Pro as my "laptop" and I am much happier. I still use a Windows workstation for everything that can't be done by ssh-ing to a Linux box, though, and of course prefer dual monitors and a mouse when I'm not travelling.)