Although more customers are satisfied with Apple's phones than any other handsets, but they're not as happy as they were last year.
The American Customer Satisfaction Index shows Apple receive a score of 81(on a scale of 100) in terms of customer satisfaction which drops 2 percent from its 2012 position.
At the same time, the satisfaction with Motorola, Nokia and Samsung grew 5 percent, 1 percent and 7 percent. And HTC and LG Electronics also drop their satisfaction scores.

That is true and expected because now people have more choices, they have more high end and innovative devices. iPhone still maintains an edge over other but as more people are becoming knowledgeable, they are ditching iPhone .. or may be simple reason is that Rich have now more options in the premium handset market.

Ya the demands and complaints are raising as per peoples expectations are also getting high nowadays, after week new technology is getting launched so people are less satisfies with one kind of thing