Because then it would be easy to pirate the games on their service. The only downloadable games shop I know which doesn't do this is Good Old Games ... probably because their games are old and cheap.
My problems with steam are philosphical also. If that weren't the case then I'd have given steam another chance when LucasArts released 'The Dig' and Indy and the Fate of Atlantis' onto the service. It takes too much control out of my hands and forces too many decisions on me which I don't agree with. For one thing, I cannot stand they way it forces me to use the latest patch no matter what and to install said patch before I can play. What if I don't like the contents of that patch? What if I don't have time to patch now and just want a 5 minute game? Tough cheese, that's what.
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