Hmm, that's probably also a big part of it. A good professional-grade laptop can last for years. I've had my 1st gen Surface Book for about three years now and it's as fast as the day I bought it. Unless something breaks, I have zero reason to upgrade to anything different.

I'm in the same boat as you at work. I've got an older MBP, and despite a dent in the screen and some trackpad issues I would rather stay with this model than upgrade to a newer, inferior one.