I really hate this trend. How did we, as a society, get to the point where financing a phone is reasonable? Why do we need to be "eligible" for an upgrade, and

I really hate this trend. How did we, as a society, get to the point where financing a phone is reasonable? Why do we need to be "eligible" for an upgrade, and why do we let mobile carriers get away with this? I wish the US was more like the rest of the world where you buy your phone separately from your mobile service.