When we're talking about Sand Veil, we need to make sure that we're talking about whether it's uncompetitive or broken.
I completely agree with this point of view.
If Sand Veil itself was broken, then why does Gliscor use Poison Heal over it?
Why isn't Sandslash broken? Or Cacturne?
The only pokemon that Sand Veil breaks is Garchomp. Banning Sand Veil is just an excuse to bring Garchomp down to OU. Looking at other Sand Veil users tells you the ability itself is not broken, it is only broken in tandem with Garchomp.
So, with simple logic dictating that Sand Veil is not broken, that means the reason for it being removed is that it is uncompetitive, since it brings in an element of luck into the game.
By that logic we should also ban Cursed Body, Flame Body, Effect Spore, Poison Point, Static, Cute Charm, and all moves that have a percentage chance of a status effect, and all non-100% accurate moves. Since these all add an element of luck into the game. How many games have been lost due to a Flame Body proc from a Volcarona?
The argument that is used for banning Sand Veil is
identically applied to these. This is not a slippery slope, as it is the exact same logic. Using these abilities and moves, like using Garchomp+Sand Veil, is adding an element of luck to the game, which is making it less competitive.
We should absolutely not ban Sand Veil. The reason for doing so is simply to free Garchomp, which should never be a consideration in the first place, banning a whole ability from multiple pokemon to free
one. Next thing you know we'll ban Speed Boost to free Blaziken, screw Yanmega and Ninjask. Garchomp is the only thing broken with Sand Veil, like Blaziken is the only broken Speed Boost user.
If Garchomp with Sand Veil is broken, that is Garchomp's fault. Sand Veil does not break any other user of the ability. Thus, Garchomp is the cause, and should be banned.
We should only ban what is broken, not what is uncompetitive, or we open a massive can of worms and need to ban half of everything in the game due to the precedent set.