I can kind of understand saying that graphic novels, novellas, and short stories are less impressive since they (usually) take less time/energy than full novels or nonfiction books. Personally, I think it's fine to count them for bingo cards or other reading challenges that don't specifically ban them. Why do you say that about audiobooks though? I'm actually more impressed by those because I cannot focus on auditory input enough to listen to a whole book that way.