I've been a software engineer for 25 years, doing Linux stuff at startups and big companies (the biggest even). In all my time as a software engineer, I've seen maybe 3 people who didn't use a MacBook Pro for work. Apple makes the bulk of its money from tech companies and schools and they cater very well to both. If it stops being Unix-like, they lose the thing they make the most money from. They are smarter than that.
Backend developers are already conditioned to use Linux VMs when developing in Mac OS.
I bet you are located in US.
You’re in a bubble. Windows is still huge, especially in middling companies that dictate it and standard HP/Dell/Lenovo hardware for all 3k staff.
It’s insanely common.
I don't think apple makes the bulk from professionals at all, the iphone is their flagship product and their laptop line has been expanding towards casual markets with budget models.