I don't know what you guys are complaining about, Steam is absolutely fantastic. Not to mention Steamworks comes with tons of benefits, like a great friend system, VAC, and Steam Cloud. Games For Windows Live, however, is a huge inconvenient, poorly coded hassle. Plus Microsoft usually restricts games it supports, by making them hard to modify, and usually being against a developer having free downloadable content.
Also, Steam
DOES NOT require you to be online to launch/play a game in any shape or form.
Well, Steam isn't all that green. I mean, their prices are horrific compared to actual store-prices. I can buy Black Ops for ~35€ in stores right now, but Steam still wants 59,99€; without a box, without a disc.
Your argument is invalid, the publisher chooses what they want to price their game on Steam.