.45 ACP is a great round but not for everyone. A lot of younger folks look at 1911's & the .45 as 'old guy' platforms. As to it's effectiveness, it's been plenty effective since the year 1911 & the .45 Colt 'long Colt' to use the slang term, in the SAA format for years before that. In fact many of the older established calibers used over the last 150 years do just fine.

In todays world a lot of camps are focused on progressing power, velocity, hyper performing rounds,. the old stuff took care of things just fine.