The only reason to me is for the ease of carry. Shorter barrels lose velocity and I am ok with the fact. I like the ability to pocket carry at times.
It's all about the mission called for the gun. I pocket carry a S&W 638 with a 1 7/8 inch barrel & hunt with a Ruger 45 Colt 7 1/2 inch barrel.
Same with the semi-auto's it's just what mission you want for the gun.
NRA life member
When the going gets tough, I just open another beer.