That's absurd. What if your cable connection goes out for a day or two (I've seen this). You can't use any of the hundreds of dollars worth of games that you purchased?! Uhg, the mentality behind these design choices is all wrong, and it's spreading. See - Diablo III.
I think the reason why the developers are going this route is because they don't want to pay the publishers, the people who print the software on CD, any of the profit.
There are a lot of upsides and down sides to this. Some of the good things are the developers don't have to worry about rather or not Wal-Mart will carry there game. And people out in the middle of no where can get the game immediately instead of waiting for it to get delivered or driving long distances to the stores.
But yea I can see why people are annoyed by this.