Why dont people consider ''family matters'' a classic like ''cosby show''?

i mean i grew up on family matters and looked at cosby show only like 3 times like they say third times a charm right? wrong i still didnt like the show family matters has more serious episodes then cosby like gun violence,rasicm,and other issues but still my mom said cosby show is above heavens then family matters why? i mean its boring at least family matters was funny!!!!!!!