True, it's not every day you see a decent-looking character with the floppy ears (what I mean by "decent-looking" is that they aren't trolls, just so I don't offend anyone). My guess is that people don't like them, it doesn't look good with their characters, or they simply aren't on a species that has them; which of course, there aren't many species with the floppy ears. I'd say that the only species they are most commonly used on are dog breeds like bloodhounds, bunnies (yes canine model), and sometimes I'll see a wolf with them. I personally like the sharp ears, so I rarely use the others. xD But I do remember creating a character with the floppy ears, and it looked purrrty.
But I'd defiantly like to see more variety to peoples' characters. ^^