The longer you have to farm something, the longer you have to play.
It’s taken 20 years for Blizzard to finally give in and make the game more alt friendly with warbands and account wide rep (for the new reps). They don’t actually care about making QoL changes. They would rather not have any at all since it just makes things less of a waste of a time for players. They only make enough changes to placate people and move on till they have to do it again.
There’s even drops in TWW that are still only soulbound. If they actually wanted to make it truly alt friendly, there would be no soulbound items with anything in the new expansion. However, that would mean actually caring about the time the player puts into the game, which they don’t.
Blizzard doesn’t care if you’re wasting your time. They only care about keeping people playing the game in general.
And not only did they nerf the badges, they are also increasing the difficulty of Timewalking dungeons/raids in general. The longer it takes you to do something, the longer you’re playing.