The "You're a pretty good pilot, here's the keys to the ship!" plot point works fine in something like Star Wars, when Luke is pushed to the front of the Rebellion simply because they desperately need anyone with a pilot's license to help blow up a giant laser moon. But the Starship Enterprise is on a long-term diplomatic peacekeeping mission around the galaxy on behalf of the space United Nations. Its job is to contact new civilizations (as it says at the beginning of every episode) and spread the Federation's message of peace and togetherness. Humanity's entire relationship to these new races will be defined by this first impression. We've seen starship captains broker peace treaties and make decisions that affected the entire future of an alien civilization.
The rebooted Jim Kirk, meanwhile, is a drunken asshole who punched his way onto a Starfleet recruiting shuttle -- at the time of his whirlwind promotion, he'd only been in the academy for three years. Giving him the job is like sending Jason Statham to negotiate peace talks in the Green Zone. Putting that cowboy at the helm of Earth's humanitarian flagship is probably going to trigger more space wars than have ever been documented in the history of science fiction, even if the movie portrays the job as being mostly running down hallways and dangling off cliffs.
"Hmm. These tense peace negotiations could use a Kirking."