It think in all our advancement, comforts and luxury we forgot to live like evolution intended us to. We're changing our environment too fast for us to adjust to it. Look at people whom live in semi-modern forest tribes, they live with nature and do so relatively carefree because they're not pushed beyond their nature (too much), nor past their culture. They've got a balance between desire and necessity.
I've mentioned this somewhere else, not sure where it was again, but we're treated- and expected to act, like machine parts, the larger machine in question being society. Think about it, from birth we follow our natural course (walking, communication and defense) and then we're dropped off in various schools throughout our entire childhood and large part of our puberty to get our ''education'' or ''firmware update'' as I like to call it. And even after that, we're expected to further update our knowledge.
Then it's time to fulfill our part as.. well.. parts, until we become too worn to fulfill our duties. Then we're replaced by newer parts. And the thing is; We're not machines. The mentality we deem normal isn't the one we got naturally, it's been put there by a globally condoned form of brainwashing. Because it's only when you are forced to think about it, that you start seeing the flaws and abnormalities of mainstream society. From a natural perspective, it is abnormal to live like 60- or 70% of the world does. We just don't see it because that way of life is passed on from generation to generation.
Now, I'm not saying it is a bad thing perse. For many it seem to work just fine, and if they're happy with it, I'll be happy for them as well. But, for those that it doesn't work for it is a huge inconvenience as they're forced between two extreme choices; Adjust to society and local culture/Return to the wild and risk death.
I've gone a bit off topic here. And I'm not really going anywhere conclusive with this, so I'll wrap it up and sum it up. :B
Long story short; there's just a lack of choice due to semi-global generalization.