I believe the .25 ACP the .32 ACP and the .380 ACP were all brainchilds of John Moses Browning. JMB was the most prolific and successful firearm designer of our time with many of his designs still serving militaries, sportsmen, LEO's, and armed citizens around the globe...HOWEVER, no one is perfect and IMHO all 3 of these cartridges are unsuitable for personal defense, even in the BUG role.
Honestly, I think they were all developed around the turn of the last century as Browning was tinkering with blow back designs before he struck gold with his tilt barrel, locked breech 1911 which enabled the use of more powerful cartridges like the .45 ACP. Of course being in business to earn a living JMB still sold production rights to these cartridges along with some nifty pocket pistol designs to fire them and effective or not, they sold quite well.
Regardless, I still consider them to be "stepping stones" on the path of invention that led to the .45 ACP and the 1911 pistol. Interestingly however, while most "stepping stone" inventions are relegated to the trash heap, "think BETA before VHS or VHS before the Compact Disk", these noisy cricket calibers seem to endure?
I feel this endurance is due soley to the tiny Carry guns chambered for them and the tiny price point they are offered at.
I'll admit, I too fell victim to the mystique of the pocket pistol when NAA introduced thier Guardian in .32 ACP and even carried it for a short time.
I'm glad I've not yet needed my CCW and very grateful I did not need it when the only thing I had was a .32 stuck in the coin pocket of my Jeans.
The ballistic data I've seen shows little difference between the major calibers of 9 mm, .40 S&W, .45ACP, .357 and .44 BUT they do show a considerable drop in performance for anything .380 or smaller.
Given the array of uber compact 9 mm's and even the new tiny XDS in .45 ACP, I see no reason to handicap yourself with a sub caliber sidearm. Especially when you'll spend the initial purchase savings on more expensive ammo over time anyway.
Just my .02 cents
Tack