The tipping point wasn't anything to do with OSX IMO. It was iOS. Still my absolutely biggest grudge against Apple is how shitty and locked in the iOS ecosystem is. I haven't wanted a Mac as a developer machine for the last 5 years but since I have to support iOS, I don't have a choice. I had a year "break" where I actually needed at Windows machine and it was a dream. Touchscreen was so incredibly useful.