I think your hate against M$ is unfounded Lucid, DLC can be free for Xbox games as well. For instance, I've had my indie games add new content in updates, and Super Meat Boy provides new map sets in their updates. I'm pretty sure it's the game companies that are usually happy to say "Okay, I'll charge a price for this", otherwise they would release the content, but at the lowest price possible (240 points, approximately $3).
Not only that, PC has had countless "DLC" like content that was sold. They were called "expansion packs". The Sims PC games still get away with selling stuff like "New shoes!", usually for much higher prices than DLC in console games.
Sure, the services are free on other consoles/systems, but Xbox includes all of those services and adds additional ones all the time using the money it recieves from its members. PSN Plus is pretty much Sonys way of collecting money to improve PSN. Free is great, but once Sony sells all of their PS3's there wont be any reason (or money) in keeping it going past making a cut on transactions.
Lets compare the Xbox Live services with Steams services:
You can't buy music with Steam, you can with Xbox Live.
You can't watch tv and rent movies on Steam, you can with Xbox Live.
You can't rate your games and content with Steam, you can with Xbox Live.
You can't video chat on Steam, you can with Xbox Live.
Steam doesn't have these services (nor PSN + Steam that is also in a consistent layout), Xbox Live does. That's what some of the $40 a year goes towards.
I'm much more of a PC gamer, so I know what I can get for free, but Xbox Live is usually a much tidier way to play the games without any hastle or worrying if my PC specs are too low/drivers are out of date. Plus, I like talking to my friends in a party of 8 while we all play different games without causing any lag ingame.