I do not find it necessary to ban non-broken abilities in any way. There is a large gap in "uncompetitiveness" that separates Sand Veil and Snow Cloak from Double Team / Minimize and Moody. The main difference is that the abilities cannot stack Evasion boosts the way the claused factors could, preventing the vicious cycle of ever decreasing chances of hitting the opponent, totally relinquishing any control from the victim after 2 or 3 successful boosts.
Pocket it has been proven by a certain user, that stacking Evasion boosts is not worth it. Only the first boost is worth the time that you spent using it. While a poke with 2,3 or 4 evasion boosts sounds good, a poke with 2,3 or 4 Dragon Dances, Quiver Dances or Calm Minds sounds much better to me. And don't tell me that after the first evasion boost the opponent is very bound to miss because this is false. In most situations your opponent will be able to kill you before you get enough boosts, simply because the odds are with his side.
And if you say to me that you can use Sub to fish for misses, then that means that you have only 2 remaining slots.
So this means that you will run either a recovery move with an attacking move, leaving you walled from a billion things, 2 attacking moves, which can still be walled by many defensive mons untill you run out of pps, or a boosting move and an attacking move, which again leaves you walled by many many things.
Take standard mons, and try to fit DT in their sets, and you will quickly notice that for most of those pokes, it simply isn't worth it. If each poke had 5 or 6 slots, then DT could be broken but as of now i don't think it is. I am of the opinion that it was banned because it would make the meta more luck based, without having enough viable counters (noone would complain if Flamethrower, Ice Beam and Tbolt always hitted).
Alphatron (or Tomahawk9?) hits a good point - you can also minimize luck by banning Serene Grace or Super Luck mons. However, we do not, because these Pokemon are manageable without excessive preparation. SJCrew also brings up a good point about Pokemon's resources in abusing such luck - some Pokemon are bestowed with more resources than their counterparts to abuse certain luck factors to excessive levels. These extra resources granted by few Pokemon had caused Shaymin to abuse Serene Grace to excessive levels, as well as Garchomp abusing Sand Veil. Jirachi or Togekiss cannot abuse Serene Grace to the same broken levels as Shaymin, just like how Mamoswine or Gliscor cannot abuse their evasion-boosting ability to broken levels as Garchomp - Jirachi / Gliscor are merely annoying with their abilities, but manageable.
Exactly. Pure luck is tollerated when it can be countered. Jirachi, Super Luck mons, parahax can all be countered by certain VIABLE methods, while evasion increasing methods can't. It doesn't matter if they break the meta, it matters that they make it unenjoyable. DT may not be worth it most of the times, but if it was allowed, many below average players would use it, winning games that they otherwise shouldn't against better players. This meta wouldn't be broken, but it would be unenjoyable. Same goes for the items and the abilites regarding evasion. Even 1 or 2 lost game out of 10,20 or 50, matters, because you should never be in a sitaution where whatever you do the match is lost, if the RNG decides it.
True, Double Team / Minimize may not be broken in majority of the cases, but we claused them anyways, because they made sufficient Pokemon broken. We cannot actually confirm this, b/c it would be so fucking time-consuming, but it's not a big stretch to come to this conclusion. I'd rather test individual swift swimmers to resolve or confirm Aldaron's Proposal than test EVERY mon that is broken with Double Team / Minimize.
I don't think we banned them for making sufficient pokes broken. I think we banned the because with these moves around the meta would be a clusterfuck, where a lucky player could be at the top 50 players, even for once in a year, because he got lucky, and we don't want that.
Also complex banning these abilities would actually be setting a precedent for banning a non-broken factor. Oh wait, there's Brightpowder / Lax Incense. Yea, let's simply not make this precedent by lifting the ban on the items that are only minor inconvenience at best (the abilities are also minor inconveniences; not enough to be dubbed as uncompetitive). Complex bans are meant to ban overpowering aspects of the metagame, such as Swift Swim + Drizzle (or Shell Smash + Baton Pass in RU?), so please don't abuse this ban method to keep Blaze Blaziken or Garchomp outside of Sand in OU.
Bans, either simple or complex, are meant to make the metagame better, imo.
This is why the evasion raising moves were banned, while they weren't broken moves, imo.
Moody was a broken ability, because it broke everything that had it. If one supports that DT was banned as a broken move, then this means that all, or almost all pokes that got it abused it to a broken degree. Is this true? No.