I use a Mac because they come with a bunch of tools that I need out of the box and are easy to use. The interface is nice and I am comfortable with it. On top of that, I have had the same MBP for 7 years. I have never been able to make a computer last 7 years before buying a MBP.
iTerm2 is a decent reason. I've tried to switch to Linux numerous times and I have yet to find a terminal app that is even half as good as iTerm. And command line tools on Windows are a joke currently, at least until the new one comes out soon (which looks good, but I doubt it will be better than iTerm). If you spend a lot of time in your terminal, being able to use the best one that behaves the way you want it to and is customizable nearly to a fault is a decent reason to stick to Mac