[mst]

This makes me wonder if there's any record of why Motorola thought that feature was worth implementing in the first place.

[lstodd]

Well I always wondered why 6502 had BCD. What was the point?

I guess it was sorta fashionable back then.

[wiml]

BCD modes only take a few gates to implement; their biggest cost is probably the instruction encoding space they occupy. On a chip as small as the 6502 it makes sense that some users would want to avoid the expensive decimal/binary conversions and do arithmetic in decimal.

[hulitu]

Maybe to drive LED alphanumeric display segments.