itunes music store rules because...
...it's not just a place to buy music, it's also a pretty good jukebox.
By that, I mean itunes as an application does a good job of organising and making accessible music to Joe Public. Sure, some people don't like the way it does things, but most do - it stores music just fine, rips CDs to your e-collection just fine, get's the track names of the cd you just ripped just fine, and syncs it all with your ipod just fine.
You've not got an ipod? who cares? Yes, I had an archos too. ipod's are better.
Once you're sat there with your music collection sorted, you can with a mere couple of clicks buy more from the itunes store - it's fully integrated. You do nothing to get it on your ipod, or add it to your collection, other than buy it. Once you've confirmed the purchase, it's ready to go.
Apple have thought long and hard about all of this; the ipod wasn't a revoltion - I had MP3 players from other manufacturers long before I bought my first apple product - but apple have looked at the long term, identified a market that didn't even exist at the time (buying music online? LOL!), and played the Japanese game of longterm investment. They deserve domination.
Every other service is destined to play pointless-catchup, and should just get over themselves and move on.
And another thing. If you don't like Apple's DRM, don't buy it. But don't buy it then moan about it. Even worse, don't *not* buy it but moan about it anyway.
And finally, I'm not an Apple 'fanboy', so get over yourselves.