I do it for a couple of reasons
1) If my rifle will shoot small groups, it give me confidence that I can make a good shot (even if it is only a 50 yard shot)
2) I want my equipment to be the best it can be.

You never know if it is you or your rifle that sucks until you shoot a rifle that is accurate.

I may not be smart but I can lift heavy objects

I have a shotgun so I have no need for a 30-06.....