I don't understand the defense for steam, it's a excellent distribution platform but some people tend to go fan boy mode over it and start spouting crap.
The defence for Steam is that it offers a better experience than all the other digital distribution services - at least all the ones that I've tried (Impulse, D2D, GamersGate, GOG, EA Downloader, etc). It has considerably improved my gaming experience and I will happily defend it against a company like EA, which has done the exact opposite.
"The price of freedom is eternal vigilance."