I see the .32's niche as more of what S&W had a bunch of years back.... a "kit" gun. Something to toss in your pack to carry along. A small, light revolver that is still bigger than a rimfire.
I had a Single Six in .32 H&R, and enjoyed it, mostly. It was fun to shoot, though LOUD,
which sort of lowered its value to me as a "kit" gun. If I'm out knockin around, and find something that needs to be shot, I really don't want to stop, put in earplugs, then try to shoot it. Especially if it's an animate type something. Even a .38 is borderline too loud, but it's not as ear-piercing as the .32 mags.
Self defense? Maybe... but I don't see the "one extra round" feature to be that big a deal. If I'm concerned about 5 not being enough, I'd probably go with a high-cap autoloader.
I like .32's... I'd love to have one of the old smiths in .32 Long. I think it would be a blast to plink around with. They just are not very high on my priority list.. more of a "luxury" type gun... one that I buy when I have most of everything else I think I "need".