So, you might remember that last year, during the playoffs, Chase Utley went on national television and broke Ruben Tejada's leg because he really wanted to be safe at second. A month prior, he tried to do the same thing to Jedd Gyorko. Now, Major League Baseball isn't a big fan of huge stars getting brutally injured, especially when it could easily be prevented. So they suspended Utley (though he won the appeal). And then, like they did with the Posey Rule two years ago, MLB changed the rules to make the game safer.
So, imagine for a moment that you're Chase Utley. You've been universally vilified for the last sixth months. There's a new rule in place specifically because you're a horrible person, and you're charging toward home plate on Opening Day. What do you do?
You try to take out Derek Norris, because you are a horrible human being. We can analyze this more closely. Norris was clearly obeying the aforementioned Posey Rule. A safer slide might have put Utley under the tag. But none of that matters, because Chase Utley is more interested in injuring his opponents then actually playing baseball.