I don't listen to rap and hip-hop and I personally despise Kanye West, whose personality I simply cannot stand, but IMO, and despite the naysayers and those who defend Apple no matter what, he does have a point, no matter how ridiculously obnoxious he is.
Since its peak in 1999, the record industry has collapsed. Even before that, only the biggest artists ever got anything from the record labels beyond their royalty advance. Most record labels saw to it, through industry accounting practices, that artists never got anything else. In fact, when Atlantic Records celebrated its 40th anniversary with a series of concerts at Madison Square Garden in 1988 (or maybe it was the 50th in 1998), Chairman Ahmet Ertegun announced that they were resetting any artist with a negative royalty to $zero so that they would presumably start receiving royalties again from that point, if they sold any records. And Atlantic treated its artists better than most labels.
Record industry revenue is now less than half that 1999 peak and that doesn't include inflation. Include inflation and it's about 40% of its former size. One of the factors in the decline of the industry is the return to the single as the dominant form of recorded media and the fact that downloads, for those who still bother, are very inexpensive. Apple has to take responsibility for a lot of that (although the alternative was illegal downloading in which the artists got absolutely nothing).
In the 1960s, singles (albeit double-sided singles) listed for $1 and sold for about $0.64 at most retail discounters. Using 1963 as the base year, a single should sell for $4.98. Obviously, it doesn't. And most artists get laughingly tiny amounts for play via digital media, whether satellite radio or digital streaming sites.
Aside from the few very biggest artists, the way that musical performers make money today is through merchandise and concerts. They do not make money from traditional over-the-air radio in the U.S., only the songwriters do via payments to ASCAP/BMI/SESAC to their publishers. Apple is a big enough and profitable enough company that they can pay acts real money, even for a free concert.
While it's true that acts agreed to appear and didn't have to, Apple is still setting a precedent that somehow, artists' performances aren't worth much. And while Kanye West certainly doesn't need the money and is a very rich man, IMO, that sets a poor precedent for other companies and lesser artists (lesser in popularity, not in talent).
Artists are trying to make a living, just like everyone else. When a group plays a 150-seat club with a $20 admission, at best, the group shares $2100, which must be split among its members, manager, agent, roadies, equipment rental, travel expenses, etc. and that's only if they're the only act. Most here are very fast to say that coverage on Apple's site is "enough". Would you work for just P.R.?
We tend to think of the big artists as selling tons of records, but the fact is that in the U.S., in all of recorded music history, only 118 albums have been certified as "Diamond" - selling more than 10 million copies. With the fragmentation of the marketplace, it's unlikely that it will ever happen again.