This is why I say that. When coming up with the criteria that a carry pistol should meet, it was all performanced based. First thing that popped into my head is that I should be able to a hit a man sized target from 50 yards (I define "man sized" as the -1 zone on an IDPA target). Other criteria that I felt was worthwhile was hit an 8" circle from 25 yards in under 3 seconds, pass the 5^5 test using 3"x5" index cards as the target, hit a 3"x5" index card from 10 yards, and pass Dot Torture from 3 yards. All that, on demand. Meaning cold, with no warm up, every time. Writing out those criteria I realized that it is as much about the shooter as it is about the gun, and that is why it depends.
If someone can accomplish all that with a Ruger LCP, then I don't see why that wouldn't work as a carry gun. Might not be the gun I would carry, but I probably wouldn't give anyone grief over it if I knew they could pass those tests.