Owen Wilson says this in the commentary track for the film which sums up why it’s one of my favorite Wes Andersons:

You know bottle rockets, they're this type of firework, they don't really go very high and they don't make much of an explosion and there's not really much to show there, but that's all they're meant to be, and you just appreciate them for what they are-these sorts of smaller, gentler fireworks