Jules: That causes inbreeding with the deer, so that is frowned upon here. Plus the United States is huge and has millions of miles of road. Fencing them all off means twice as much fence, which is a huge cost to our limited budget already... So we don't do that...

As for society entering their territory, yes and no, but the real reason they have become out of control (and why we need hunting) is because humans fear the predators more so then abundant deer. The worry of one of these predators taking a child, a dog, some sheep, is more threatening than 'excess deer', which is wanted by a large population anyways... so that is the way it is.

BTW, Deer cost insurance companies billions of dollars a year, but it also spurs ten fold that in other industries... I know areas where I live that live on 6 weekends a year... the hunting weekends. :-) It is very wanted by society in general, and many that live in big cities don't understand, nor take the time to learn.