The item changes were reverted because they were garbage...I give you your point that the buffs they gained should also have been reverted, but the changes they made to the AD items were at best garbage, and at worst actual sabotage in an attempt to force bruisers into bot lane. It did a lot of damage to the gamestate when Riot tried to force the change to happen. It had nothing to do with not wanting bruiser bot to be meta at that point, and more to do with gutting an entire class of champions because Riot wanted the meta to change that much.
If the meta changes, then it changes. If someone breaks about 20% of their game to try and force that change, then sure, it can happen, but now about 30% of your player base is about to quit the game for an actual good reason (that reason being that you then show you're not afraid to completely throw an entire caste out the window to make another caste feel better).
As I mentioned, I understand ADC mains can get pretty whiny...but that was one time they actually had the right. It'd be the same case as what OP said: you want to shove an entire player base full of champs out of top lane just because you think they should go elsewhere, you're gonna piss off the people who play those champs in top.
And on top of the buffs ADCs kept, we now have a load of new runes that heavily favor pubstomp/faceroll champs over champs that are supposed to live against faceroll champs and actually fight back...so at this point, adcs, mages, assassins and divers are quite a bit stronger than they need to be. I'm not calling for another tank meta, but at this point, changing the runes to not give so many free aggressive stats would globally nerf damage and result in something far easier to balance. Runes should give primarily damage, defensive stats, and utility...not a bunch of lifesteal, lethality, tower toppling and CDR. Damage, defense, and utility, so that defensive runes still actually work against offensive runes, and utility runes help both sides get around each other better without just giving someone the ability to just yeet off anything that moves.