Ankle holsters are silly.
Perhaps, but then don't wear one.
Personally I find one useful at times. Rather than carry speed strips for my J-Frame pocket revolver, I find it more convenient to carry a S&W 3913 as my, "Reload of choice". My personal choices are 1) belly band, 2) camera bag, ankle holster. I find that each of these have pluses and minuses. Then so does carrying a firearm have pluses and minuses.
I reckon there are folks that truly think their personal view of the world ought be the way for everyone. Perhaps the OP ran into one of those.