Here is what I think they should have done:
Have the movie open with a montage of the park opening, people laughing and enjoying the sights, etc. Then, show it (in the same montage) falling apart through some terrorist attack or something, and everyone scattering into the jungle/dying.
Have the premise be that some sort of high-ranking official or someone of importance is on the island but trapped at a facility deep in the interior, and the one way to rescue them is on foot. The movie would follow a rag-tag group of commandos/mercs as they work their way into the jungle to save them. They would start off on ATVs but would eventually have to slog through the marshes/tall grass, etc. They would fight a few raptors, outsmart them, and then eventually take down a T-Rex or something. There would be no genetically-altered smart dinos, nor any tamed raptors. Just a bunch of manly men kicking ass Predator-style as they try to save whoever needs saving.
In the end I don't even care if they save the person, the movie isn't about that. It's more similar to Dredd in that it's just about the mission, not about the goal.