I still wear them! :) They're still about! It's just that the high street shops aren't stocking them at the moment so nobody can buy them :) There's a lot less of the traditional denim skirt but if you look around you'll see a lot of girls wearing denim skater skirts!
Denim mini skirts are like jeans... they never go out of style! Certainly makes sense for casual wear for anyone to wear in place of shorts on a hot day. They work for guys as well as girls. Even better since there are no crotch binding seams!
I still see denim mini skirts being sold in stores sometimes, but I agree you don't see many people actually wearing them around in public. I think they've died out somewhat because the high rise, super cropped top stuff is what's really coming in right now and the denim mini skirts weren't part of that style. (I want to say like 80's or something??) Cut off denim shorts were part of that style also and I think part of the reason people don't really wear denim mini skirts anymore is because they're not very comfortable and even though people still wear skirts these days way more people wear shorts because they're easier to wear and more comfortable/versatile. Also denim mini skirts give off a bad-girl sort of vibe which some people don't want to achieve. This is just my view on it though.
Well same thing as no girl wears bows, scrunchie hair bands, or pigtails anymore. thats all 90s bull$hit.