Anyway, 6502 is a super easy processor to program on. Back in the old days (and maybe even still) universities often used non-existent processors for teaching assembly language programming and associated concepts. I learned 6502 as a child on my Apple II and even when I went to university, I always thought it was a much better first starting place simply because it lacks anything complicated at all.

To be honest, even though I have fond memories of 6502, if it were me, I might have chosen 6809 since it gives you a few more facilities and makes a couple of things a bit easier. But it's not crucial...

You can certainly learn using a more modern processor, but there is a lot more stuff to keep track of. The idea of starting with a super simple processor and then graduating to a more modern and complex processor makes sense to me.