Multiple .45's? _Well, for multiple reasons...
I am currently not a handgun owner, but when I was several years ago, I had the following, and for different reasons:
Colt Series 80 Lightweight Commander - because it was the first one, and a good deal.
Colt Series 70 Gold Cup - because it would take the wear of lots of shooting better than the L.C., and because it was nicely gunsmithed for IPSC - a good investment at the price
Colt Officers Model - (blue) because I wanted a .45 that was smaller as a carry gun, and when the O M came out, it was only available in blued (black) finish.
Colt Officers Model - (SS) because I really wanted my carry gun to be stainless - it would wear better and not be subject to rust/corrosion on externals.
At the time, I also had these others:
Walther PPKS in .380 (blue) because it was a great CCW when I was in social situations, more compact than a .45
S&W 686 for HD, because my ex-wife was more comfortable with a revolver, and her comment was, "Anything less than a .357 is boring."
Browning Hi Power 9mm - the worst trigger I've ever owned! It came and went fairly quickly.
Colt Woodsman, made 1947, in cherry condition, original box. Because I bought it for $350, and simply couldn't say "no" at that price!
TC Contender in .44 mag, with 14" barrel - Just because having a handgun that was a "two-hander" was really fun!
The 686 went with my ex- when we split up. I got rid of the Hi Power because the trigger was atrocious. The Colt Series 80 and the 2 Officer's Models went to pay for the divorce, as did the PPKS. Later, when I moved to NY State as a new bachelor, the Gold Cup was sold to a NYS Trooper, and the Woodsman went to a friend for his gf . I didn't use the Contender, so it went, too.
I am currently wanting an M&P .40, but new (young) wife is expecting twins, so that'll have to go on the back burner for now.