Here's my theory about the demo and steam. For better or for worse, Hl2 is built around steam, it probably is integrated deeply into the code for the game. To release a demo, valve had three options: 1) recode the game to not use steam at all, which might take a lot of work. 2) release a demo that, like hl2 full, needs steam to run. 3) not release a demo. Now from purely a business standpoint, it might not be good business to put a ton of work into a free demo. So they released a demo integrated into steam. I don't see anything particularly evil about that, at least not any more evil than anything any other company does.