Radioshack, BB, Apple store employees receive different degrees of training, all of it inadequate.
They are likely not put in a position to succeed as the computer systems they use are not coordinated and don't allow them to extract information.
Central command doesn't have coordinated policies on pretty much anything.
And the employees do not have any skin in the game; they can tell you whatever they want without any repercussions, so they have no incentive to serve you. My impression is that most of them aren't that interested in working there; they are just there to collect a paycheck. Honestly, I probably wouldn't be all that interested to work there either.
The shining star employees would shine no matter where they worked. It has nothing to do with corporate policies. I've found that Apple employees are a bit better trained, and usually friendlier, but ultimately not significantly more helpful or different than the usual places.