Baskin-Robbins has 31 flavors, and heavy metal has about twice as many subgenres. At the rate metal critics are subdividing their acts, itll get to the point where each band will be the sole representative of its own genre. But metal isnt alone in this similar nitpicking can be found in just about every larger music community, from folk to electronic. Its a bit like looking at a magazine rack there are publications for every interest, hobby and fetish you might imagine, from gun, car and nudie mags to philosophy and astronomy journals. A band does not deserve to be placed in its own genre for playing "doo-doo-da" well the other bands are playing "doo-doo-dee." Catering to fan demand is one thing, but the real problem is labels telling the band what fans want and then making fans want it through advertising. Many of the most commercially successful artists are those who play to their genre-determined specifications to a tee. Imagine the Zac Brown Band attempting a cover of War Pigs, for instance worse than sounding ridiculous, they'd risk losing their fanbase, a chance fewer and fewer artists are willing to take. Depending on the genre, there might be a moratorium on certain instruments, singing in certain registers, using certain chords, or singing about certain subjects. An adventurous artist would never self-impose these kinds of arbitrary restrictions.