They were also a LOT of fun to program as you could really learn every bit of the architecture. Being able to do edit/compile on a modern box and download to something like the Atari makes it a lot nicer than native development was in the day. (IIRC, back in the day, some folks would cross compile on DEC boxes for similar reasons.)

I'd probably do a lot more 8-bit work in my spare time, but bare metal embedded systems scratch similar itches for me and, well, folks will pay for that sorta thing. :)