Knoxxus said:
What do you need them for? Why not just make more genres?
Because having a list of genres half the length of the list of albums wouldn't be very useful.
For example you want a "pop - chart" style genre and have to click through 30-40 other genres to get to it. However if you have say 10 "global" genres you click to "pop" (less than 10 clicks) and then click to "chart" within the "global" genre. Thus, halving your clicks and speeding up your browsing.
Say you're in the mood for Hip-Hop but only, say, east coast Hip-Hop, you would then go:
Hip-Hop>East Coast>All>Shuffle etc.
Much better, and if you can't see why you: i) don't have very much music or (ii) never browse by genre anyway.
From the attachment you can see you get a list of 50 or so artists rather than 200. - A bit easier to find what you want on an iPod