Apple reigns supreme with people who have higher purchasing power than others. That’s the niche they want to maintain, not total market share.
If we're talking about Real Computers, Linux is more rough around the edges, sure. But it has Freedom. And it's a fantastic system for software development.
So it went. I can’t trust it. Not only that with Google’s business model I can’t rationally invest in it. Oh and the handset was abandoned after 12 months. My backup iPhone 5s got an update on 14th June at 7 years old.
As for real computers, yes. The Mac I have is a nice terminal for Linux on a server but Linux on the desktop is not rough round the edges: it’s a nightmare for daily use.
If you use it as you would use Windows or Mac OS, then there are no more issues with Ubuntu from my experience.
I actually prefer Ubuntu over the other two as the web developer experience is much better than Windows and Mac OS. It's nice to use native tools. It's nice to be able to trust profiling. The same is also true for the other two where you would have to use replacement software on Linux.
I do most of my dev work in linux but using the Mac as a terminal.