The Votans are like the Xindi or the Covenant of the Halo games. They are a multi species ailen group that wants earth but unlike the Xindi or the Covenant they want to live on it instead of destroying it.
The back story says that they have terraforming technology. If that is the case, why didn't they head to a Goldilocks planet that has no sentient life and take over it. Humans have nukes and certainly will not take kindly to aliens arriving with planet terraforming technology.