That's not the reason it's done!!1 Do you honestly believe that that is the motivation behind the hunt?what about killing for pest control?
Living in the area that I do, I know several masters of the hunt and all would privately admit that it's done for sport and for fun, despite their ridiculous claims that it's done as a method of culling. As stated before, if they did want to keep the fox population under control, they would employ a more effective and efficient means of doing so.