I was pretty sure it was because getting people to write drivers in Objective C for DriverKit was never going to reach any mass appeal, so better make it C++
Yep. Everyone writing drivers for Windows/Classic MacOS/UNIX was doing it in C. And Apple wasn’t particularly confident that ObjC would appeal to even application programmers (hence the Cocoa-Java push, and the never-finished ObjC “modern” syntax)
http://unix.superglobalmegacorp.com/cgi-bin/cvsweb.cgi/objc/...