It depends on where in the world you are, and what sort of development you do. I rarely see regular business app developers with Macs where I am (South Africa). Indeed Macs are generally used by the wealthy here (weak exchange rate+middle-income country), or those who need to develop for iOS. Universities either use Linux or Windows in CS labs.

A huge percentage of the developer community worldwide uses Visual Studio, and most run it on Windows, rather than a Mac running a VM.