Bacon, you don't guess, you know. That's a great post you have there and ultimately the embodiment of just how many questions are raised by this proposal.
Hugendugen said:
Proponents of the ban argue that it limits the teambuilding process and is ultimately uncompetitive, while opponents argue either that we should never ban Pokemon or forms from Ubers or that Mega Gengar simply isn't uncompetitive enough to warrant a ban. There is a precedent for removing aspects of the metagame that are almost entirely luck based or incredibly uncompetitive, for instance the OHKO, Moody and Swagger Clauses. The aim of this suspect test is to gauge both whether we are comfortable removing a Pokemon form entirely and then whether Gengarite or Shadow Tag as a whole in fact are sufficiently uncompetitive.
This paragraph sums up what people think and what this tests the playerbase on. I applaud Smogon for pushing boundaries and when it comes to banning, but all in all it does come out as somewhat hypocritical if you assess the mindset of the elite players. Smogon's philosophy has always been to create a stable metagame, but Ubers has been by far a tier above the rest and out of the jurisdiction of the typical bans. There's a certain degree of freedom in the tier where gods fight gods and mortals (OU) often struggle to keep up, as if Ubers is a sanctum. It also holds true to its own definition of which Pokémon reside in it (as Auride mentioned, by community vote). Our test is if we want to bring such a giant gradually down to level with the rest of them and make it the new OU hypothetically. Like bacon has said, this is a very controversial topic, and the test isn't so much about Mega Gengar as it is about ethics and philosophy.
Mega Gengar was broken in OU, yes, and he certainly holds his own in Ubers by the look of it. The magnitude of Gengar's trial is in essence whether we want to change views and handle Ubers as another tier subject to the traditional ban list or let it exist as an independently working entity with its own restrictions as it always has. By virtue, Ubers has been an overcentralizing, different metagame and entity, and the majority have been fine with that, simply eliminating what we consider "luck-based"; do we want to reconsider? Now that the question is upon us, we either attack the problem - Shadow Tag - or let it be and cherish the current special qualities of this tier. Already, there's intense debate over whether Ubers is a tier renowned for balance and subject to the term "uncompetitive" just as much as OU or is a tier for uniqueness and the challenge of fighting with titans.
tl;dr, this is a controversial topic indeed, and one that raises a ton of ethical questions. It's more about that than Mega Gengar or Shadow Tag however, and if you are focusing solely on that (hey, Gothitelle), you are missing the big picture.