Lies, damn lies, and information on PC hardware boxes

I don't really understand how PC hardware manufacturers get away with writing the rubbish they do on the boxes.

Apparently, according to the box on my new wireless ADSL router, wireless G is only good for Web surfing or email.

If I want to download an MP3, I need wireless G+.

If I want to do online gaming I need wireless G+ MIMO.

Streaming video? My goodness I'll need N1 MIMO.

According to this I shouldn't have bought the router. Completely inaccurate sales spiel on a box that tries to dissuade me from buying it? Why and how do they get away with these lies?