I got one word for ya: Spectacle.
In all seriousness, though, they're after the same thing as most of the canon "Team X"s: Resetting either society or the World (or Universe) to how it was in an earlier time period.
I mean, look at it: Aqua wanted to reset the world back to how it was before the continents formed, Magma wanted to reset the world back to before the oceans formed,the first Plasma wanted to reset the world to how it was before Humans and Pokemon had learned to work together, Flare wanted to reset the world back to before life had come into existence, and Galactic wanted to hit the reset button for the entire Universe.
Looking at our game, Team Meteor wants to reset the Reborn Region back to how it was like before Humans arrived.
The only exceptions to this are Rocket and the second Plasma, which both just wanted to accumulate power; and Team Skull, whose motives we don't know yet.
The similarities are strikingly apparent, don't you think? So why not have them either nearly or actually succeed in their goals?