The slippery slope already happened, in case you weren't paying attention. Drizzle + Swift Swim changed everyone's attitude toward combination bans, and dozens of proposals have come up since then. Darkrai + Dark Void, Blaziken + Speed Boost, Garchomp + Sand Veil, Sand Rush + Sand Stream, and now Snow Cloak + Snow Warning. Up until the recent SmashPassing ban in RU, none of these things have come to pass either (and if it were up to me, I'd have seen Gorebyss, Smeargle, and Huntail BL2, but alas).
After all is said and done, I suppose it's too late to keep complex banning out of the minds of the people, but there's no ordinance proclaiming we have to let it infect our policy. God forbid I'm somehow convinced that bringing back Drought is a better solution for the current metagame, provided we were only allowed one Chloro Sweeper and Charizard and Victini were not allowed on the same team. The possibilities for balancing Pokemon through complex bans, unlike balancing a tier through hard bans, do not end. The latter solution is a straightforward path to success only opposed by a handful of dissenters who somehow believe it would be better for the metagame if we kept hail through sheer favoritism.
Let me get this out in the open. I want to ban Snow Warning because all of hail has an unhealthy effect on the metagame. Teams stacked with Ice-types discourage the use of slower Pokemon weak to them, such as Rhyperior, who does indeed become dead weight whenever a Hail team is present (just as he did when Drought was around), and the passive damage rules out the effective use of offensive items such as Life Orb for fear of being [very easily] stalled out. There are very few Pokemon immune to Hail's passive damage and the metagame has simply shifted in favor of those who take beatings from Hail not quite as poorly, despite reaping no tangible benefits from it all the same.
Now riddle me this: what benefits do we receive through allowing Hail to run amok? Currently, I am seeing none. Unless you are WhiteQueen I don't see anyone using Hail because they like it. Also, unlike Drizzle or Drought in OU, not a lot of Pokemon can take advantage of a free Blizzard, save for Ice-types, who also have abilities specifically designed to abuse Hail. Who or what is this save helping besides the obscure Ice-types that were already abusing Hail?
EDIT: Small excerpt from an unofficial senate discussion that I found pretty funny
17:27 JabbaTheGriffin: sjcrew do you have anymore replays these are fun to watch
17:27 upstart: he has a lot of replays
17:27 JabbaTheGriffin: you just play like absolute shit, get hazards down, your opponent misses a bunch, and you win
17:28 JabbaTheGriffin: it's like you don't even have to try lol
I will answer to your post in 2 parts.In the first part i will explain what prevents complex bans from getting out of control and in the second part i will explain what are the benefits of keeping Snow Warning around:
What prevents complex bans from getting out of control:
First of all simple bans are always our main and first solution for balancing the meta.
We resort to complex bans when we can't fix the problem in the meta with single bans.
Also when making a complex ban we have to make sure that the benefits outweight the negatives.Notice how this wasn't the case with single bans.Regardless of what happened after a suspect was banned,we banned him/it anyway because it was broken.
For example a broken threat could be keeping other broken threats in check,and the banning of said threat would lead to an even more unbalanced meta.But regardless of that situation we would still ban that threat simply because it was broken.But with complex bans we can't think so simply because the suspect is a whole situation and not a single factor(ability,pokemon).
For example when Aldaron's proposal was introduced,it got accepted because the positives (diversity,balancing other weathers) outweighted the negatives (banning non broken pokes in Drizzle conditions).
So the thought proccess about bans goes like this as far as i have understood:
1.Fix the problem with the more simple solution(simple bans)
2.If the problem cannot be fixed with step 1 then fix the problem with the next simpler solution (simple complex ban)
3.If the problem still cannot be fixed with step 2 then fix the problem with the next simpler solution (not so simple complex ban)
4.So on...
Your example of allowing Drought back if only 1 Chloro sweeper was accepted in each team,and without Victini and Charizard won't happen because there are much simpler steps.
Banning the ability because the majority of the Chloro sweepers or sun abusers that are competitive viable(we are not taking into account shit like Charmander right?) were broken under it was the simpler solution and so we chose it.It was clear which the broken factor was!
But in our situation it is not that clear...Snow Warning does not break the majority of hail abusers(or even if it does we have no evidence as of now).Snow Warning breaks only the majority of Snow Cloak abusers! There are many more Hail abusers like Blizzard spammers and Ice Body pokes that are just fine under Hail.
So we cannot resort to step 1,which is a simple ban(Snow Warning or Aboma/Snover/Froslass) and we must go to the step 2.
The source of all the major problems is the commbination of Snow Cloak + Snow Warning! And this is what we should ban for now! We should choose the next simpler step which is the simpler complex ban!
Of 'course as SJ Crew said some guy could propose a ban of only one Hail abuser and not allowing Snow Cloak users carry the move Substitute but this wouldn't be the simpler solution!
It is true that with complex bans there are infinite possibilites but we are wise enough to seperate the rational from the irrational ones!
What are the benefits of keeping Snow Warning around:
By keeping Snow Warning we manage to keep one major playstyle(hail teams) and 2 or 3 team archetypes(Hail Offense,Hail balance,Hail Stall).
We also manage to keep more than 5 pokes in UU (by keep i mean keep them as UU viable not UU by usage) with Snow Warning present such as Walrein,Glaceon,Rotom-F,Abomasnow,Cryogonal and some more that i may forget...
So instead of losing all these pokes why can't we chose the complex ban which gets us rid of the major problem(misshax from Snow Cloak)by nerfing hail and making it manageable,at least in theory,with zero negatives?
And before anyone says that we should chose the simple ban because according to my thought proccess the simple bans are the step 1 of the banning proccess,i have to say this... We chose to make simple bans when they are fit for the situation and when they don't ban something that isn't broken! Snow Warning isn't broken on itself,nor it provides unparalleled support. It only breaks some pokes when the ability Snow Cloak gets in the mix!
Sry for this wall of text but the whole matter with complex bans is pretty messed up and i had to speak my mind! Thx to anyone who spent his time reading all this...!
