The problem with that is, they will be held accountable for delivering those advertised speeds.
In other words, they're upset that AT&T's vacant marketing hype posing as a genuine technical specification is diminishing the value of their own (and better established!) marketing hype posing as a genuine technical specification.
How...frustrating.
In 3G (or 4G, whatever) the speeds are dependent on a lot of things you can't really control: amount of users, location, the 3g device, weather, etc etc. So you can never really promise "with us you'll get at least x megabytes per second!". On the other hand, you could advertise the "maximum speed", which is also meaningless since nobody ever gets that.
and every consumer should multiply those speeds by 0.707