Most developers use Windows. [1] The second most popular OS is Linux on Stack Overflow, and some of those may be running Macs.

There are certainly groups where Macs are popular. Startups use a lot of Macs; when I go to a coworking space in Boulder mostly everyone has a Mac. They're super common in cafes as well.

But not everyone uses a Mac. Not everyone likes Macs (myself included).

[1] https://insights.stackoverflow.com/survey/2017#technology-pl...