I think, this is much about another major difference in the history of both designs: while originally for a different architecture, the DP2200 processor / Intel 8008 was meant to be a CPU for a small computer system from the beginning. The 6800 and in consequence even more so the 6502 was more about a microcontroller for implementing in software what wasn't economically viable to be put in silicon. Notably, it was not meant to be a computer CPU. Thus, the 6502 falls short on many things like support for large stacks, as required for higher languages, or efficient 16-bit operations. (Its philosophy may be better described as, "if it runs, it's good enough, even better so, if it runs cost effectively.")

PS: regarding the DP2200 not being meant as a small system, I'm not so sure about this based on my own reading. But, certainly, it wasn't marketed as such.

And, regarding the educational merits of the 6502, it may be a good second language, as it requires you to think about your implementation. (Personally, I'm more for the PDP-1, which Ed Fredkin – "world's best programmer", no less – once claimed to have inspired IBM's RISC architecture. ;-) )