Well there are some people I know who have 3DSes who are dumb. Yes you can play DS games on a 3DS. If Nintendo is starting to put that label on their games, then the confusion is more widespread than I thought.
it is put on the label for the same reason do not eat is put in ant killer....because people are dumb....the average parent has no idea about backwards compatability, so they see that and understand it will work with their kids new game system.