People get bored. There was thread a while back on Reddit, about discussing free ice creams and chocolates at Google. Thread bought out a very interesting aspect of human life, some people complained about quality of some chocolates in the fridge. So here you have a people who are getting free food, chocolates, ice creams, massage centers, toys and what not for free. And yet after some time they continue to have complains.
People will always have something to complain about. Besides look at the communist set ups. They aimed to provide what you say. Yet all of it went in the drain. When you award things uniformly for non uniform efforts. The concept and specialty of distinction goes away. People don't feel compelled to try a little extra or go the extra mile because there are no special rewards for that.