Why is this thread degenerating into a "can Air Balloon Luke check Excadrill" thread? With regards to the OP, I don't believe that a Pokemon needs to be dominant in itself to be an Uber. A Pokemon could be Uber because of other Pokemon allowed in the tier. Lets take a hypothetical example, lets say that Aldaron's proposal was never passed, and the Swift Swim+Drizzle ban was never implemented. Politoed would be termed as "Uber" even though its really Kingdra, Manaphy, Ludicolo, Kabutops, and Thundurus that are dominating the metagame. If those Pokemon did not exist, Politoed would just be something that counteracts Sand or something. Similarly, in the case of Deoxys-S, it would likely not have been deemed Uber had Dragonite, Cloyseter, Terrakion and the like did not exist. The "Uber" often has as much to do with what other Pokemon are present than the abilities of the Pokemon in question.
Another way of saying this is if the burger didn't come with fries and a drink, your happy meal just wouldn't be as appetizing.