Why does GTA 4 get so much hate?

[Farsala]

The missions were terrible. Go on a mission and then I have to gun down 100 people alone, no allies. It was just inhuman and quite annoying. After you gun down 100 people you have to run from the cops everytime because you killed everyone else that was guilty. I liked GTA4 but it was more of the same if you have played earlier GTAs.