releasing a demo after the game is out is like not letting critics to see your movie before the general audience ... Of course there are those who don't like to admit that they've wasted their money and will vehemently defend it on this premise alone.
What the hell are you blathering about? Since when were you forced
to buy the game on release day?!?
Read carefully: You're allowed to wait for the demo before deciding whether to spend your money.
Frankly, releasing a demo after the game is the very best way to convince me that the two might possibly be based on the same code, and therefore that it is
demonstrative of the retail product. This used to be the standard way of doing things, and it was better.
go outside, read a book, play a classic, go get wasted, write a program, buy some shrooms.. fucking enjoy your life rather than wasting it in this anticipatory state.