While I can agree that the 2015 offers a better value for the money, and is a very, very good laptop, I don't see how it's superior in anything compared to 2016, let alone 80%. In fact, it is worse in almost every way (still great, though).
If you got a 2015. one - it's a good choice, maybe even a smarter choice, but let's not get unrealistic here. The new MBP is faster (faster GPU, RAM, SSD, CPU doesn't throttle as much - so faster), it is lighter, it is smaller, it has a better and brighter screen, has better battery life for the most part, it has a better build, it has a better trackpad and - for a lot of people - a better keyboard.
In fact, there are a lot of reasons. You don't have to agree with them, though. I prefer the USB-C ports to the old ones.