Part nostalgia, I grew up with various home computers, with their respective video game musics and demoscene demos. Chiptune also tends to have a nice adrenaline videogame rush feeling to it. On the other hand I just like weird and eerie soundscapes, whether they're generated with some modular synth monstrosity or ancient computer hardware.
Also I have a lot of respect for 80's chip design. They were sure clever with the limited resources they had and given that they had to do everything by hand, they achieved a lot.