I always looked at ankle carry as a sort of last ditch, hole card type thing.
It was just very comforting knowing it was there, out of sight if things went really really sideways. I was never under the illusion that using it would be fast or pretty, but as I say, if I had a ***** with my primary, or lost it, God forbid, that Model 60 on my left ankle was a comforting thought. I will add that I never came close to having to use it, but I practiced with it like it was imminent.
I also know a lot of guys that couldn't stand ankle holsters. Same with shoulder holsters, similar thing I guess.

ETA,I found out you cannot use the acronym for Fouled Up Beyond All Recognition, who knew?