6502 assembly was the first language after Apple Basic that I learned. I found it to be a very enjoyable experience. These days it would be tedious, but back then it was fun making the limited hardware do something and the only thing you used is what the hardware gave you. Today we have it lucky... with all the frameworks, libraries, and such only a small percentage of the end result is your original work. That's great for efficiency, though the downside is you can't point to a program and say that you wrote 100% of it.

I imagine this is similar to how someone who likes to tinker with engines might prefer an old motorcycle they can take apart and put back together themselves even though there are many advantages in terms of reliability, efficiency, comfort, and so on to driving a Prius.