I would actually consider grunge to be a genre. But as far as all of the discussion about labels, there are too many currently. Rock probably has 200 sub-genres, along with metal, alternative, etc. Tool is usualy labeled Progressive/Alternative Metal. AIC...in the 90's....was labeled as Grunge/Metal.
Music evolves. People may not like it, and I can think of alot I don't like, but what is currently fitting into one genre, can change over time.
I think we can all agree that the banRAB being talked about, are some of the greatest.
Note: (No one has to reply saying something about my 200 genres comment. I am merely exaggerating to get my point across.)