Understand that I deeply love the single action platform for all-around shooting, but I wouldn't pick one as the handgun of choice for a defensive weapon. Even Elmer Keith switched to double-action Smith & Wessons during his later years. While you seldom see them in movies, during the last third of the 19th century Colt (and others) sold a lot of double action revolvers, and an examination of period photographs and literture will show their considerable popularity.
That said, the S.A. style still remains an excellent choice for an outdoorsman or woman where speed of shooting and reloading is less important. This is especially true where heavy loads in largebore cartridges is involved.
Never the less, as improvements in arms came along, westerners were quick to upgrade, and this was the point I was trying to make.