Sorry to contradict you but quite a few of the employees at video games stores DO know what they are talking about. It's their job. I used to work at EB and we prided ourselves on knowing as much as we could about the industry. When were things coming out? Who canceled a release and why? Will there be enough Xbox 360's for release day? What types of gameplay are in what game? Our ability to know our subject is what seperated our store from the Gamestop's of the world. And our customers were very loyal because of it.
Yes, some stores *cough* GameStop *cough* do have incompetent help. It's unavoidable. Much like Walmart, sooner or later you are going to be stuck hiring the bottom of the barrel.
However, the employees that you met, were you nice to them? Or did you treat them like sales drones? I rather suspect that if you treated them with the contempt that you show in your posting, they didn't want to talk to you.
On further thought, I rather suspect that there is at least one GameStop store out there that isn't staffed by rejects from the local literacy campaign.
While I have moved on from the not so glorious world of retail game sales, I felt it appropriate to provide an alternate view.