I have always liked .32s because they are so cheap - and pleasant - to shoot. And they are accurate, too. (If you don't handload, you may want to forget it.)
I can't answer your question about using the gun for protection. I used to take one of my various .32s along on dog-walking detail but that was about all I used mine for that might have been considered "carrying."
I know a lot of .32s were used for personal protection back around the turn of the last century but I think there are so many better options these days that it might be a bit short-sighted to rely on it now. That said, a sturdy .32 Magnum handload is nothing to sneeze at!