Blame it on the Hollywood suits I honestly don't think the movie is worth an 8, not in its released form. But since the cuts and additions from the suits are so painfully obvious, I'm willing to give a higher rating to the movie that could have been... and for now, only the original director Oliver something has seen.
So the original movie (which is still discernible somehow) was supposed to be a dark, slow take on isolation, pill overuse and boring modern life. With a twist: a mom so desperate to protect her child, she would silently watch other people being killed as long as she can find her kid. That's actually moving and seldom seen in a macho-dominated Hollywood. I won't say that ice cold Kidman is the right choice to depict a desperate mom, but given that her role is to often look emotionless (so she can pass as another "pod people") she doesn't do too badly.
Now, the suits didn't like that and called those soft-brained Wachowski bros to make it -supposedly- more mainstream. And what they did was to add car chases, crashes, helicopters, fires and senseless violence in general. Inserted into the original movie at close intervals to keep people amused (or so they thought). Now, there are a few good directors who can pull out a combination of slow burn and crazy action. But a patchwork movie made of two different directors' bits, guys with widely opposed instincts and goals, no wonder the result is a flop.
If anything is to be learned from this, it's how little do Hollywood executives know about what makes a good movie. Granted, a non-stop mishmash of violence and fifth-drink bar philosophy like The Matrix can earn the big bucks, but you can't expect Matrix-like bits to improve what was intended to be a slow paced, moody film. Which was probably condemned to be a box office failure, but also could have been pretty good.