Here's a little background to where this question came from.
#1. I'm not made of money, and I don't like to own a lot of "things". Therefore, if I can have one gun fulfill a multitude of purposes, that is my preferred option.
#2. I'm a "practice" fan. If $100 dollars will buy me a better gun, or more ammo to practice with the gun I've got, I'll put the money into ammo.
#3. I'm a sucker for heroes of the old West and the American frontier.
So, I have a Ruger Blackhawk .357, and I just love to go to the range, strap on a genuine leather belt, fill the cartridge loops, and blast away. A big part of what makes it fun is the imagination factor. So I shoot the gun a lot specifically because it has a "cowboy" flavor.
If I owned a 9mm, I can honestly say it would likely get left in the safe at home.
The likelihood of ever needin' a gun for defense is extremely slim the way I live.
So, it seems to me a waste of money to buy a semi-auto if I'd end up taking the .357 anyway.
If the times ever change to the point where I decided it was necessary to practice with an uglier gun, I suppose I would switch.