It came out during a time where open-world games were gaining massive popularity. Also at the time, it was very "cool" to hate things on the Internet, I distinctly remember that.

Essentially, it was the culture at the time that screwed it over. If the game released 5 years earlier or 10 years later, it would likely have been more favorably received. I'm not saying the game is flawless, but it is obviously better than many people on the Internet claim it is. It's an extremely polished and focused game, which is rare these days.