[ Marco Arment ] Here are some reasons why:
The 13-inch non-Retina MacBook Pro model number MD101LL/A is simply ‘101’ among Apple employees according to Marco Arment. If hardware tinkering is your thing, the 101 is the last MacBook you can do that with.
I too used to tinker, with my 2009 17-inch MacBook Pro. I replaced the HDD with a SSD and then replaced the SuperDrive with the HDD. I even got a software tool to reduce the frequency and voltage of the CPU so I could take out the two fans. Fan noise drive me up the wall. Check out Silent, Cool, Green MacBook Pro for all the details.
I don’t tinker anymore; I now prefer an iPhone-like experience: solid state (no moving parts, except for the buttons and the mute lever) and silent. I want to simply use it. And the most iPhone-like MacBook? The 2015 MacBook.