Same reason some people currently carry a 38 revolver, others a 380acp, others a 9mm, a few 357 sig, some others 357 mag, a few 41 mags, some others 40sw a handful of 44spl, a lot of 45acp, and then the majority who carry nothing. It's what he had, got good with, and for one reason or another liked better than other models available. I always wondered why the colt guns were so much more popular than the Schofield until I saw the floppy loading arm the Schofield has. There is only one person who ever POSSIBLY knew the answer and he died many years ago at a poker table. Ask a man why he prefers a 1911 over a HiPower...most folks don't really know why they like one over the other.