If you look at market share for consumers, Apple is doing much better.
HP, Lenovo and Dell still rule the enterprise, but Apple does very well with consumers. And more and more enterprises are moving to cloud based solutions, buying tablets and negating the 'need' for PCs, even if for the time being they're still buying cheap PCs.
I can't imagine a company pushing for tablets as general purpose devices for a lot of things... as a POS (point of sale) terminal, or even for standing sales reps, sure...
But real productivity is so much worse in line of business applications on a tablet vs. desktop. Screen size/space is king, and nobody is going to work on a 20" tablet... or give up half the screen to a keyboard. Let alone how tired will your arms be by the end of a day without a mouse for anything.
I know you can tap a keyboard/mouse to a tablet, but at that point, you've spent more money than a low end laptop or desktop, with worse productivity and output.
If we limit the scoop to consumer computers, including Linux seems odd. At least in Sweden extremely few people are using Linux on their computers. Even with Macs it's less than 30%.
Can you clarify why big brands should switch to Linux for their consumer PCs considering that few consumers wants it?
HP, Lenovo and Dell still rule the enterprise, but Apple does very well with consumers. And more and more enterprises are moving to cloud based solutions, buying tablets and negating the 'need' for PCs, even if for the time being they're still buying cheap PCs.