Just let me briefly summarize for the sake of clarity, what was most important to me:

a) genres could help (especially new members) find musicians that have similar asethetics, without in any way implying that this would lead to avoiding listening to other styles of music.

b) i love the idea of exchanging ideas about songs (my own and those of others), but am not fond of rating/grading a creative effort by another person. This seems to me fundamentally wrong to grade art like that, and cannot possibly help people create better art. If you want to let the artist you that you love their work, a "well done, i really loved that piece" goes a lot further than tagging on some percentage.