The problem with video game shops is that they aren't specialist stores, but they should be. I don't know what it's like outside of the UK but here the problem is that GAME (and Game Station) are just run like shops with product on the shelves you pick-up and buy. I see this as a major problem because video games are very specialist and unless you know exactly what game you want to buy, it's a hugely confusing experience.
They treat every customer like a hardcore gamer who knows what game they want, knows what day it comes out and they come in, grabs it off the shelf and heads to the till. They aren't catering for the rest of the market (which is much, MUCH bigger than the hardcore market) that generally don't know what's good and what's bad, and more importantly what's suitable for whoever is going to be playing the game.
If you were to go into GAME and say "I want a Wii game for my 7 year old daughter, it's got to be fun and colourful and easy to play and nothing nasty etc", a typical GAME employee wouldn't have a clue on how to recommend you. They would most likely pass you Mario Bros. Wii, which would be completely unsuitable as it's a hardcore game. FOR EXAMPLE.
GAME, or any other shop that sells just video games should be like a Hi Fi shop, or a car showroom, staffed by people who know what they are talking about, have knowledge about every game on the shelf and can sit down (yes, sit in a sofa in a nice area of the shop like there used to be) and demo the game to the customer and talk to them. I would put money on that most of the staff in GAME know very little about the games they are selling, and for the staff that do, it would only be basic knowledge on the big AAA games like FIFA, or Gears or Halo. "Yeah this FIFA has the 2012 roster, and they've now got 8 player co-op" or whatever. Basically they've just read the back of the box. Sure, there are gamers that work there, but they don't play everything that comes out or would even have decent knowledge on them.
I put the blame with GAME for not looking at what a video game shop should be about or training their staff properly. I remember when Future Zone (which changed to Electronics Boutique, which changed to GAME) would let you play games before you bought them to see what they were like. I don't know why they changed that as it was a great idea.
Would people abuse it? I don't think so, and people abuse anything so thats BS and can't be used as an excuse. It's the same as going into a record shop and listening to it before buying it. Shops like Fopp/Head allow this and it should be the same with video games.
That's my thoughts anyway. Gaming is too specialist for it just to be a shop that sells stuff, it needs to be more than that. Is this the reason GAME are going down the shitter? Most likely no, but I can't say I've ever had decent customer service in there when I've been, they just try to see you crap, recommend the Used version of the game and tell you how good the game is when it's only been out a day.