I think it's safe to say you know where I stand. For me, I see two angles but both are a pretty simple philosophically in the end.
First, it's a race. The head to head competition will bring more out of most people than what would essentially be a time trial would. Also, if you get to know yourself well, you'll better be able to set your pace based on what you are capable of by feel than by looking for splits. What if you're more fit than you realized or you're having a particularly good day? Running by splits may result in selling yourself short. Likewise, if you're having a bad day, running by splits might get you in over your head.
Second, it's a matter of personal experience. I used to run for a coach who would work with us to come up with our goal splits for a race. Both of us being a numbers guys, we took those goal splits a little too seriously and I essentially committed to running them. When I committed to them this way, I'd often end up with a subpar performance. When I'd essentially say screw it and just run, I'd surprise myself and Coach. I remember one 10,000m specifically where I was going a second per lap fast. Coach started off telling me I'm too fast, I'm too fast. By about 2 miles, he stopped giving me splits and just started cheering for me to pick off the next guy. I ended up with a 1:15 PR, essentially running over a lap faster than my old PR, and a time around 30 seconds faster than we had set for my goal.