Of course tiering is about power. It has been about power for almost two years now, with the descriptions of the Uber Characteristics. And we must adhere to these descriptions or else the "slippery slope", or rather, a more ban happy environment can possibly occur, where people can arbitrarily complain about things that annoy them, and desire them to be banned for "detracting from the game." While that may seem an exaggeration, I feel that such a stance is entirely the wrong stance to make when creating the perfect competitive environment. It no longer becomes a specific set of rules that dictate what we ban, but rather whatever we feel should be banned to make a more fun battling environment, and while that is a seemingly noble effort, a system like that would do more harm than the one we have now, which, like it or not, is based around the power of the pokemon.
It seems to me, however, that the controversy around Salamence is around the fact that he doesn't truly fulfill one of the three characteristics. I will even concede that he does not. He is, in my mind, the definitive borderline case of how close we should stick to the Uber Characteristics. I admit he cannot wield the ability to say that under standard conditions he can sweep large portions of teams with little to no setup. Nor does he make it easier for others to sweep by breaking walls (Which I frankly find to be a rather roundabout and unjustified way to argue Mence as Uber, that only came to surface because they know they can't argue him under Offensive). And it is because he cannot claim these, he cannot be defined as a true Uber.
However, I believe to fully understand why Mence should be Uber one must rather look towards why we had to create the characteristics and why he fits into that reason. I think it's fairly obvious that the reason we ban Pokemon is to make it so that the Metagame doesn't overcentralize to a handful of overpowered pokemon, and to, as a side-effect of the ban (and not the reason), create a more fun environment to play competitively in. It is for this reason I think Mence should be banned, as he DOES centralize the metagame to himself, and without him we no longer have to bottleneck our teams to having a Bulky Water and a Steel Type to take care of him. This allows more diversification in team building, and more variety in overall play creating an arguably more fun environment to play in.
While one could argue that the metagame has been Bulky Water heavy and Steel Heavy for a very long time, and also argue that they have other valuable uses, one must also remember that 3 out of the 5 banned suspects in Generation 5 have been the Dragon Type, which directly affects the usage of those pokemon. Bulky Waters have been around for the purpose of abosorbing the extremely powerful STAB Dragon Moves and OHKO with Ice [Insert attack name here], and the Steels became prevalent not just for their fantastic defensive typing, but also for their sole ability to resist the Dragon STABs. Now, in an environment with Garchomp and Lati@s gone, the Bulky Waters and Steel tanks are still very prevalent. This is because of Mence. Salamence is the last bastion of the powerful, overcentralizing Dragons in OU. It is for this reason I argue that he be banned, because while he cannot claim to easily sweep teams, he is still able to overcentralize the metagame by, through sheer might, keeping the now overlooked tradition of using the natural Dragon type "counters" in the Meta.
Edit: Seems as if the conversation shifted from when I started writing this post. Oh well, point still stands.