RE: deer rifles
Guys buy magnum rifles for the same reason they buy a 1 ton 4x4 pickup to drive down the highway to the grocery store. Because they look and sound cool!
BTW, I have never owned a rifle that shoots a belted magnum cartridge. I've killed whitetails with everything from a .243 to a 577/450 Martini-Henry, but it's more because I'm a shooter rather than a hunter. I've never shot more than 5 deer with any one caliber, always playing and experimenting.
Hunt with a magnum rifle if you want, it IS a free country.