Alternatively you could just take whatever steps to make each metagame as diverse and enjoyable as possible. There's nothing inherently wrong with the ban; rain is nerfed, because a function of its versatility and therefore overall effectiveness is nerfed. However, rain is not ineffective or inviable. The drizzle + SS ban is an example of making the metagame better without limiting its versatility.
The only true disadvantage of complex bans is their complexity; and this point is mainly for newer players trying to get into competitive battling.
Banning a pokemon or ability often has severe knock-on effects for a metagame, this disruptance is not as strong when compared to a softer ban. It's a simple; what is broken > how can we fix or balance it > what method is best to fix it for the metagame in general. In this case; ridiculously fast and powerful SS rain sweepers with unlimited rain > ban SS + drizzle or the other options > SS + drizzle being best because it fixes the problem whilst maintaining the options of drizzle, SS and the pokemon in OU, which maintains versatility and has small knock on implications for the rest of the OU metagame.
I mirror Miscellaneous's sentiments here. Outright ban of Pokemon or Ability disrupts the metagame drastically. Banning Drizzle / Politoed in Round 2 would have been a very rash decision. By banning Drizzle you are not simply banning an Ability, but an entire playstyle. Aldaron's Proposal provided a logical, rational, and even scientific way of dealing with the problem - remove the broken variable (not any additional variables associated with it), observe the impact on the metagame, and then act accordingly.
Seems people are going against the idea of complex ban for philosophical reasons (ie "nerf"ing strategies are NOT allowed!) or because of its novelty (we've never done this before!). In fact, history of Pokemon has been full of these nerfs and novelties. Latias / Latios without Soul Dew under Soul Dew clause (effectively nerfing Latias / Latios) during Gen III and the No Sleep Perish Trapping clause (Mean Look + Perish Song + Sleep Move) during Gen II.
This is a new gen, guys, with new problems. With new problems, we must not be afraid of adjusting our ways of dealing with these unprecedented threats. Weather had never really been an issue in OU, but this gen it was brought down from Ubers to OU. Weather is a complex issue, influencing the playing field the match takes place, and thus providing certain teams advantages and others disadvantages. It involves an interaction between Abilities. Simply banning the Weather Summoner or the Weather Abuser can be the simpler and correct decision, but may very well be a rash and crude decision (for the sake of "simplicity / consistency"). Weather especially deserves a more careful inspection, and sometimes a combination ban is the best route in eradicating the problem.
Some players have in fact concluded that this current metagame is balanced. Others have concluded that Drizzle itself is indeed overpowered (not simply Drizzle + Swift Swim). If voters with reqs vote that Drizzle is not broken this round (although that remains uncertain), Aldaron's Combination ban will exist indefinitely for the good of the metagame.
Never was it agreed upon that Aldaron Proposal was to be "temporary." Such a statement is merely a rumor spread in the Suspect Discussion thread. There is no need to lift the ban if it effectively solves the issue at hand.
Rather than focusing on the odd nature of a particular combination ban, pay closer attention to the problem at hand and how to deal with it. And of course the impact on the metagame.
Garchomp vs Sand Veil + Sandstream
As for Garchomp vs Sand Veil vs Sand Veil + Sandstream ban, it is arguably a more isolated case than Drizzle + Swift Swim issue. Only Garchomp effectively abuse Sand Veil to intolerable levels. I am relatively indifferent about this case (meaning I can see both sides). I can understand people wanting a ban on Sand Veil or Sand Veil + Sandstream due to the 100% activation of this retarded ability, because of the pairing of Ttar and Garchomp. However many find such ability bans as absurd, since Garchomp is the sole abuser in OU.
Personally, I prefer to ban Sand Veil + Sand Stream because it would have a lesser impact on the metagame (greater impact - loss of a very distinct OU Pokemon), and we can observe the influence of Garchomp on the metagame with less Sand Veil activation. Not only would Ttar's usage fall with 1 of the top Sand Abusers prohibited in tandem, but also the usage of a particular set, Subchomp, and its blatant exploitation of Ttar's Sandstream would also drastically decrease.
Why not simply blanket ban Sand Veil? This is simpler, but leads to absurd consequences, such as the loss of access to Gen IV TMs and Tutor Moves, as well as a ban of Cacturne from OU.
Now a valid argument would be that Sand Veil + Sandstream Combination ban has a larger impact than a loss of Garchomp, because it would affect other Pokemon. However, if you think practically, I believe we all can agree that loss of Garchomp would be a much greater impact than the inability of Sand Veil usage in Sandstream for Sandslash (which has Sand Rush), Gliscor (which has Poison Heal), Dugtrio (which has Arena Trap) or Cacturne. IMO, the influence of the combination ban on the metagame is minimal, and we are simply eliminating the prominent luck out of the game.
Smashpassing
I feel it is early to render this particular strategy as suspect, since it seems like a relatively new, manageable, and unpopular strategy. However, if it does become an intolerable issue next round, I wouldn't call out on people who nominate this combination of moves to be banned. I wouldn't ban Gorebyss, Smeargle, or Espeon due to its association, since they have so many viable uses. Gorebyss is still a nasty Sweeper with Shell Smash, and Espeon has extreme utility in Magic Bounce. If Smash + Passing is a problem, ban Smash Pass. Don't Ban Shell Smash / Gorebyss / Espeon for the sake of "simplicity / avoid setting precedents." If you haven't noticed the req voters are not stupid. They wont nominate Level 65 Mewtwo into OU. Relax.
Speed Boost Blaziken
This is a very special case, the most isolated case of all the examples. It doesn't involve weather and Speed Boost isn't inherently retarded. Whatever decision we choose (banning Blaziken as a whole or only SPeed Boost Blaziken) may most likely not disrupt the metagame significantly (as opposed to banning Garchomp / Drizzle). I personally would support the release of Blaze Blaziken, since it probably will be viable in OU with access to Drought, Flame Charge, and / or HJK. However, I can perfectly understand here where the complications from adding this specification to our OU banlist would outweigh the potential viability of Blaze Blaziken in OU.
Although this is a done issue this round (since Ability + Pokemon ban is not allowed), I would not hesitate to nominate Blaze Blaziken whenever it is aloud, since I believe "complexity" should be a non-issue if it makes the metagame more diverse and balanced.
IN SHORT: Opposing Combination Bans due to its "complexity (what complexity?)," "setting precedent," "nerfing (lol, nothing new, blasphemous, or avoidable - you are already nefing some playstyle by banning Pokemon)," and not for its influence on the metagame is ridiculous. Aldaron's Proposal has been an excellent attempt at balancing the metagame while keeping a playstyle viable. Ban Playstyle if it is broken in its entirety. Be open to Combination Bans that offers flexibility and potentially better impact to the metagame.