Some guns just aren’t necessary

I am racking my brain to figure out why anybody would need a rifle capable of accuracy at greater than 100 yards. For home invasion? Nobody has a 100-yard-long property. For hunting? Give the poor deer a chance!

The only answer I can think of is that a 100-yard range rifle is for murder. Why is that legal in a civilized country? Or maybe I should rethink the concept of my living in a civilized country.