Nope, nopenopenope. You're objectively wrong.
So, only focusing on the movie and not the book, we can still show the island is a colossal failure before Grant and Co. ever set foot on the island.
Remember, they're only up for the weekend. It's a three-day tour of the island. On the first day, Nedry brings down some security systems, and they reboot the island. On the second day, Grant finds a cracked egg on the island. While not explicitly stated in the movie, the egg is the exact size, color, and texture of the raptor eggs we saw first. So, to start with, dinosaurs are already breeding, which means the park is already out of control; since the egg has already hatched, we know this has been going on for some time. Second, dinosaurs (or, at least, raptors) are now demonstrated to have already escaped their confines, even before Nedry was able to do anything.
Nedry disabled some security systems, but left all the dino pen systems in place. When he didn't come back, the only way to bypass his lockout was to restart the entire system, which then ran on auxilliary power and thus wasn't powering the fences, so all hell was free to break loose and it was much, much easier to see the failure. But the park had failed well in advance, they just didn't know it yet.