Well he might be but he's s**t at flying space ships and clever handsome and brave Lord Nelson would turn in his grave if he found out what he was up to.
It stands to sense that if you have a ship with warp drive, bristling with lasers, then the thing to do is to fly it about caning people and taxing them.
Find a primitive civilisation with no space travel? Perfect! Cane them with your lasers and rob all their stuff. Then pretend to be their friends and make them work for you, exploiting their own resources.
Romulan cargo ships? Stop them and make them pay tax on their cargo, or cane them with your lasers and take all of it.
Borg being a pain in the arse? No problem, cane them with your lasers and haul their poxy cube back to Portsmouth for prize money. And put any crew that survive the caning in a zoo.
But no, it's prime directive this and peaceful quadrant that isn't it? The big fanny.