How am I biased? I hate the Nu52 Superman and most of the other titles.
Everyone has biases.
I didn't judge the movie until I actually went to see it. You are judging the movie based on someone who wanted their book on Supermans origin on the big screen and didn't get it.
Actually, he got quite a bit of his book in there, as he himself mentions. If anything, that should have made him an unabashed supporter of the movie.
Waid didn't want his book on the big screen; he wanted SUPERMAN on the big screen. And when that "Superman" killed, he realized that he didn't get what he wanted.