I'd like to make several nominations of abilities I'd like to at least have people consider moving to B Tier:
Guts - this is a good ability, but it both requires that something want to use physical attacks and have the speed to be able to take down things without simply being wrecked in the process (see Ursaring). It's also not that great on anything defensive since using it would near certainly require using a status orb which would greatly decrease their ability to sponge attacks. It isn't an ability that can be slapped on any Pokemon and make it better (useless to things that are more specially based or defensive) and requires a stat spread customized towards attack and speed to work well. I suppose an argument could be made that Special Attackers could maybe run mixed sets with it or defensive threats could get a boost from being paralyzed or something, but I just don't see it.
It requires physical attacks, no speed. Even stuff like Ursaring is terrifying given the right support. Most physical attackers would be better off with guts, especially due to the immunity to Burn damage. I believe that is what referred to in "doesn't require specialized stat spread and moveset" means REALLY specialized, not something along the lines of "must use physical attacks". If over half the metagame can make potent use of an ability, I'm pretty sure that qualifies it as A-tier.
Magnet Pull - Another good ability, but I'm not sure it deserves to be A Tier. For something to be effective with it, it requires your movepool to either have set up or ways to kill steels (customized movepool) along with either the power to kill steels combined with the defenses to live long enough for them to not kill you or the defenses to pull of substitute shenanigans like Magnezone (customized stat spread). For example, Probopass has Magnet Pull and is still largely useless because it lacks these characteristics. It also has somewhat of a more specialized purpose in that it only is useful against steel types.
Probopass is largely useless because it's Probopass, and a perfect example of why Magnet Pull is A-Tier instead of S-tier. Again, A-tier doesn't have to make the Pokemon it's on go from crappy to great. That's the S-tier's domain. And honestly, you don't have to be very specialized to kill steels: you just have to not be Probopass or another equally shitty mon. Anything given the ability to trap Pokemon can usually do something with it, especially with all the defensive steels like Forretress, Ferrorthorn and Skarmory roaming around. Virtually anything with set-up moves can take advantage of those three, and anything with fire or ground type moves of decent power can trap and kill various steels. Again, A-Tier does not have to be good on absolutely everything, but it does need to make most Pokemon the better for it. I think Magnet Pull does that, if only because it gives so many Pokemon the ability to set up to ludicrous levels.
Moxie - I feel similar to guts about this one. It's great on physical attackers (provided they have either enough bulk or speed), but on a special attacker or defensive mon it's not going to do much. I'd say this is especially true for defensive mons as, if I remember correctly, Moxie doesn't activate if something dies from indirect damage.
Same argument as Guts; the requirement to use Physical Attacks does not "Specialized moveset" make. While not every Pokemon would like it, almost any physical attacker would, a massive part of the metagame. Additionally, it's flat out game changing when it does activate. A free +1 to attack can win games in and of itself.
Quick feet - If you're using it you need either high enough power to kill while on the clock from the status orb I'd presume you're using, some form of reliable recovery to keep you around longer (if you're a special attacker with a burn orb, this would be less helpful for a physical attacker since it would need to hold a toxic orb), or the bulk to pull off some sort of rest set. It also doesn't really help anything defensive that much since they don't want to be burned or poisoned anyway. I suppose they would get a boost from being slightly less slow when paralyzed and from being faster the turn they wake up from sleep or unfreeze, but I don't think that's enough for A tier.
You don't need to use a goddamn Toxic Orb or something to have Quick Feet be useful. Quick Feet is useful in its own merit because Status Moves are VERY COMMON, so getting a free speed boost from them is pretty damn awesome for almost any attacker. Again, "must be offensive" isn't a big enough restriction for it to be considered a "specialized moveset". If MOST Pokemon benefit from it, it fits. This isn't the S-Tier, it doesn't need to be universally good on everything.
Sand Force - Requires a movepool with good ground, rock, or steel moves you want to use (customized movepool), only boosts the power of moves of three types and only if a sandstorm is active (more specialized in purpose or effect), gives immunity to Sandstorm but so does Magic Guard which is also currently A tier (inferior to other A Tier Abilities in this regard)
This one I do agree on, as "three types of moves" is a lot more restricted than "Physical attacks". The vast majority of Pokemon would either not benefit from this or benefit very slightly in the form of a slightly powered up EQ. While I don't agree in your comparison to other A-Tier abilities with the Sandstorm immunity, I WILL say that the immunity is a rather small factor in and of itself. It's nice, sure, but unless you're fighting Sand-Stall it's unlikely to be a game changer. There's a reason Overcoat is in the D-Tier (though maybe it does deserve to be a bit higher than that, but that's for another time). Overall, this ability simply makes too little an impact to be A-Tier. We tend to forget that since one of the Pokemon that gets it (Landorus) is perhaps the best user of the ability there could be.
Swift Swim - Let me make clear this is only due to the fact that Drizzle+Swift Swim is banned (if we aren't taking that into account for the purposes of this list I retract this nomination). Swift Swim would be a solid A tier ability if it weren't for this ban, but because of it, it only really is useful if your opponent is using a rain team or, I suppose, if you're using a rain dance team. I feel like that is a bit more specialized of a purpose than other A tier abilities are from my understanding.
No no no, for one, I'm pretty sure we're not supposed to be looking at these abilities in regards to the bans placed on them (or Moody would be F-tier since nothing can use it). Swift Swim is ridiculously powerful, and the only reason it doesn't dominate right now is because we took steps to see that it wouldn't. And even in the current climate, SS is seriously potent simply because of how common rain is in the metagame. You don't even need to run your own rain starter these days; you can simply use it to shred apart opposing rain teams. Swift Swim is definitely A-tier, without a doubt.
I acknowledge that there are probably good reasons for keeping a lot of these where they are, and I'm perfectly willing to be persuaded the other way. Currently I'm feeling iffy about them though.
Also, on another note, I'm not nominating it, but I think Mold Breaker has been inadvertantly removed from the list.
