First thing you should do when you get a guitar from a shop is put on new strings and set it up correctly. For Electric that means adjusting the pickups and bridge to the correct heights and setting up the intonation.

I use to run a guitar store so I know first hand that the guitars on the wall have been sitting there sometimes for up to a year or more under hot lights, with the same strings.. hanging in a place where hundreds of people keep picking it up and trying it with their greasy fingers.

Not to mention that the guitars that come from some manufacturers (particularly the lower priced 'combo' type of stuff) are usually out of tune and badly set up with a very cheap set of strings.

Another big difference in the playability of certain guitars is the quality of manufacturing. There's a reason for the difference in price between a $100 guitar and a $3,000 guitar for instance. Usually most beginners will spend about $100 to $300 on a guitar and think that's as good as it gets. They keep wondering why they can't get it to sound as good as the guys on albums or TV but never quite catch on the the fact that it's the guitar that's at fault and not necessarily your playing.