Simplicity, flexibility, strength, support, looks.
Can be a bit heavy depending on build. Not sure the BR is any less expensive than some competitors offerings in this segment.
Transition changed the game when they released the Bottlerocket. I credit them for the slopestyle revolution and the sudden switch to shorter travel bikes from big hit bikes that took place a few years ago. While the Bottle is no longer the lightest or best in the this segment, it's still one of the best bikes ever made in this class. I was able to put a Hammerschmidt, Marz 55, drop post, and some lighter components on this for what amounted to a very versatile bike.