mrhappyface said:
Because its fun and cool to hate something popular. Guess why so many people hate Harry Potter and Twilight.
I'm pretty sure the issue with Twilight is that it's poorly written, and promotes codependency. As for Harry Potter? I'm less sure, but something along the lines of poor continuity comes to mind.
Modern Warfare 2 has developed a backlash based on serious technical flaws. Feelings of betrayal for a number of players who were fans of the series (both for the alleged console bias, and poor PC support as well as the technical problems).
And, while it's cool to hate things that are popular, that kinda doesn't explain the intensity, last I checked IGN's user reviews were hovering around 2.3/10. That's not a minority of people hating something because it's popular, that's the majority hating it.