When circumstances change, there can be a new cause to ban something.Hey man, just because something wasn't banned doesn't mean it shouldn't be. Ever heard of Salamence or Latias?
In the case of Salamence, the circumstance that changed was the banning of Latias. On the other hand, in the case of Latias, no circumstances changed, and it should never have been banned.
Ratios aren't important here. It took virtually no effort, and therefore it cannot be considered a waste of much effort, if any.It's a waste of effort considering how much it did. It you do a ratio of even the slight effort of writing one more line of code to get it banned on how much it achieved, it is still huge (Small number/A very small number still is a large number). It's like Singapore's ban on chewing gum in the streets. While it really isn't a big deal and doesn't spend much effort to enforce, at the end of the day it is something completely trivial. If it's not broken, don't fix it.
It is an official decision, but it shows how nitpicky and ban-happy this place has "officially" become. If it's not broken, don't fix it. Why don't we ban stuff like Fire Stone or useless items? They're uncompetitive because they're useless. If it's uncompetitive, do we ban it? If we left Brightpowder/Lax Incense in, was it making the game any less playable than it is now? Not by any measurable amount. I guarantee you people would still complain about hax when we remove it. Again, it was a seriously pointless that achieved virtually nothing. Why waste the effort to achieve nothing? What's even more baffling is why we're not banning Sand Veil/Snow Cloak first. The logic of this place is absolutely astounding.
Being useless doesn't make something uncompetitive. Brightpowder and Lax Incense were banned because, while on average they aren't useful, they have the potential to allow an unfair victory for the player using them, which may be different from any fair victory the player might get from any more consistent item.
As for Sand Veil and Snow Cloak, they weren't banned because a blanket ban on the abilities would result in the banning of Pokemon such as Garchomp, which are not inherently uncompetitive. I proposed an alternative method of using a combination ban to prevent the abilities from actually taking effect in any battles that are likely to happen. The real problem here is that my proposed alternative was ignored, despite being a near-flawless solution.