Home decor is a highly personal thing. Part of the fun (possibly the only fun) in moving is that you have a clean slate to decorate however you wish. If you want to buy an absurdly ugly rug, go right ahead. You're the one who has to live with it.
The only thing I can think of that would make me put one of these rugs on my floor would be if it were to cover something hideous going on with the floor underneath it, and that would only be if I had no other options. But for most of these rugs, it would take a real catastrophe in the home to cause a large enough problem with the floor to make me willingly lay one of these rugs down. That's what insurance is for, to protect you from having to put rugs like this on your floor. Kind of.
I don't know why people have these rugs, other than bad taste in novelties, but here are 14 of the most outstandingly obnoxious rugs we've ever seen.