I imagine the 6800 series might have taken off more if Apple had used it. It was somewhat successful in the 8-bit market.
The 68000 series of 16/32 bit CPUs was a viable alternative to x86 in the 1980s and was used by Apple (not to mention other vendors) for about a decade. When Apple/IBM/Motorola committed to PowerPC in 1991, that was presumably the beginning of the end for the 68K series.
Amusingly Apple shipped its first ARM-based system (Newton) in 1993, while the first PowerPC Mac didn't ship until 1994.
