(Turns out I went from citing
this a little bit to really a lot. If you haven't read it yet, do.)
It's amazing how knotty an issue this has become. However, I'd suggest that there are two major points in contention here: the degree to which luck is appropriate in the metagame and whether Smogon should write its rules on the basis of simplicity and ideological purity or in a more ad hoc pursuit of the best possible metagame.
The first point isn't really about Garchomp at all. Hurry up and test it, see if it's still broken. I'm not going to try and theorymon it, but Salamence sets a precedent for a big, bad metagame-breaking threat becoming rather tame when the metagame shifts. If Garchomp is still broken? I don't know. If it isn't, then it seems like common sense to drop it down to OU, adding another little layer of complexity and interest to the tier--to namecheck the Characteristics of a Desirable Metagame, we do want Variety, don't we?
It's about Sand Veil, and it's about luck. Again, citing dougjustdoug's write-up, the degree to which luck should play a part in the metagame is not clear. Should we abolish critical hits and ramp up all accuracy to 100%? God, no. The Flamethrower/Fire Blast debate is just about the single most interesting thing to happen during my time playing Pokemon. When I started, back in third gen, the conventional wisdom of the time was unequivocally
against 120/80 moves with nice, safe ~90/100 alternatives. I mean, you do more
damage, yes, but at what cost? You have placed yourself into the control of the Dice Gods, and those bastards can be fucking brutal.
But then people started doing more maths, and something wonderful happened. (This always happens when someone starts doing some maths.) If Pokemon X uses Flamethrower on Pokemon Y, it deals 75-85% damage, and then Pokemon Y scores a clean KO on its next move. But if X is running Fire Blast, however, it deals at least 95% damage--an OHKO with SR! Fire Blast is unreliable, it has only an 80% chance to get the kill. But Flamethrower has a 0% chance to KO. Fire Blast is clearly the superior option in some contexts, on some Pokemon--Flamethrower is in others.
Luck deepens and adds complexity, it adds to the quality of Skill. A Skilful player will be able to determine when Flamethrower is appropriate and when Fire Blast is appropriate. Awesome. But what about the
other side of luck, the Serene Grace Jirachi/
random goddamn fucking crit side of luck? Sometimes, luck renders skill moot. A string of Iron Head flinches is, to me at least, inappropriate (if only because it never happens for me). A player's skill has no bearing on whether or not Iron Head flinches, and the outcome of the game appears to be determined wholly by chance. This luck is bad, right? I use Scald. Everyone does, it rocks. It's a fun thing though--one could argue that Thunderbolt's 10% paralysis chance is not why they chose to use Thunderbolt, but the only reason people use Scald over Surf is the 30% burn rate. I consider
this fine.
TL;DR: In discussing whether or not Sand Veil should be banned (or the extent to which the Evasion Clause should be extended), we much acknowledge that different players have different expectations about how much luck should affect the metagame. Instead of discussing whether or not it is "broken", perhaps we should discuss whether or not Sand Veil is, as an ability considered unto itself, a source of an unreasonable amount of luck.We should endeavour to reach some clear consensus as a community about how much luck is appropriate.
Is an ability's distribution an inherent part? (To wit, does the fact that fuck-all actually uses Sand Veil factor into the discussion?) I guess, on some level, distribution counts. If more things got Shadow Tag, we'd certainly be discussing that. It's this sort of question that feeds into the other major point of contention: the pragmaticists versus the purists. (Heads up, I don't know which camp is in the right, if either. If it seems like I'm favouring one camp over the other ... sorry.)
The purists want a clean ruleset for the metagame. This isn't just fussiness, there are clear benefits to a simple set of house rules--clarity, for example. If people are able to learn and understand all of Smogon's rules easily and without fuss, everything would be goddamn wonderful. We, as a community, don't want to be seen as the pretentious pedants busily over-complicating an already pretty complex game. In a perfect world, the rules for OU would be simple: a list of banned Pokemon, a list of banned items, a list of banned moves, a list of banned abilities, Sleep Clause.
But this isn't a perfect world (fuck yeah,
Candide!). The Swift Swim/Drizzle ban can perhaps be seen as the first great victory of the pragmaticists. It's a complex ban (
shock! horror!), which has, in my opinion, been "better" for the metagame in the long run. Rain is no longer the be-all and end-all of OU (although still potent), and weather wars have added another layer of variety to the metagame which would be a shame to lose. But there are pitfalls to this mindset also. Consider the Cacturne. We don't see much of him in OU, but in the lower tiers Cacturne gets some green spiky action and adds some wonderful variety to the meta. Cacturne has the ability Sand Veil, which is nice, but not central to how he plays. However, forcing Cacturne to use his DW ability, Water Absorb, causes him to lose access to some of his more interesting moves. A pure pragmaticist mindset would insist that we should have different rules for OU and below (Sand Veil banned in OU, allowed for Cacturne in UU), or that a special exception be made for Cacturne in the Evasion Clause.
TL;DR: You're not stupid, and you've almost certainly figured it out. The absolutes of ideological purity and ironically pure pragmaticism are not healthy for the metagame, or for Smogon's reputation. We need a metagame that is fun, diverse and competitive, with reasonably simple rules. We need to strike a balance between the two absolutes of the purist and the pragmaticist.
What is the ... point of all this? Well, perhaps that dichotomies are fucking stupid, and should instead aim somewhere in the middle. Purity or fun? Total lucklessness or a clusterfuck of luck? We need to know we are talking about, we need to reach some consensuses about what we actually want from the metagame, and then let these consensuses inform how we make decisions. Cool?