it seems to poor little musically illiterate me that half these subcategorisations are ways for the bands to say "look at us, we're special and different" and for brown-nosing musical critics to validate the salaries they get paid..
do I recognize the various examples sound different? yes..they're different tracks by different bands.. I'd feel cheated if they didn't sound different.
that said, half the subcategories, I feel, have little reason to exist.. and the same happens with metal (where half the categories should just fall under one big label called "bad music with no discernible melody or lyrics")
or maybe I just don't understand it and it's my fault.