Why in the heck would someone put a carpet mat on top of the rubber ones in the first place? Maybe the issue occurs when people put the rubber mats on top of the carpet ones. (But I still think this is counterproductive to the whole point of buying these things). I bought the rubber ones so my carpet ones wouldn't get ridiculously dirty during the winter months.

I haven't had any issues with mine. I get the feeling people don't understand how to install a set of floormats, and Toyota is trying to make them idiot-proof (maybe they will just put a big label on them - "Don't install these over top of your existing mats").