Lets say you buy a game on the Steam store. Now lets say that game is so bug-ridden that you can't play it. It's so bad that you can't even run the game. You check online and it's such a big problem that the CTO has publicly apologized. You contact Steam support to ask for a refund. They tell you to forget it, so you contact the publisher. You explain that you have liked their games forever but this game is not playable. You want your money back. The publisher will tell you that you need to get a refund from the retailer you purchased the game from. It's out of their control because they don't have your money.
You contact Steam again, they tell you that they will issue no refund. You threaten to file a charge back from your credit card company. Steam says that they will disable further purchases from the Steam Store if you do so. They actually state that they will not let you purchase any more games from them if you protect yourself as any consumer should be allowed to.
Somehow, I just can't imagine doing business with them anymore.