TL;DR: Achievements being nerfed feels bad for people who have them completed. Creating a lower initial tier of achievement would solve both problems and keep both completionists and more casual mount hunters happy. (But please keep reading.)
First I want to say that my complaint about these nerfs isn’t calling for a reversion of the nerfs. I’m suggesting that there be better implementation of good intentions on the part of achievement development.
I fully understand that the BFA meta achievement “A Farewell to Arms” was too ambitious of a meta in its first iteration. It would have been very cumbersome for people who don’t traditionally do completionist achievement hunting. Some things needed to be removed from the meta; for example: PVP Island Expeditions being removed was an exceptionally good choice that no achievement person refutes.
But seeing the achievements we’ve already accomplished being nerfed outright? That’s…a slightly different solution to a overly-involved meta. These achievements aren’t unachievable now. They’re incredibly time consuming and take a lot of grit and resilience to complete, for sure. But that is the core aesthetic of achievements in World of Warcraft. They are intended to be a feature that most players won’t always unintentionally complete through regular gameplay. And the points that people have in their achievement collection are a reflection of the effort they’ve put in. The time doing it, sometimes the skill needed, the research completed, or the strategy in accomplishing large collections.
You should have just made all of these nerfed achievements a brand new first tier of two achievements. Like it’s fine if you want to make it “10 of” instead of “all” - but you should have made a new achievement instead of reducing the ones we’ve already completed and devaluing the work we’ve already done. Why devalue stuff we worked so hard for. Those achievements are still doable and you could have made lesser versions of all of them to satisfy more casual mount farmers. For example, instead of nerfing “Combating the Corruption” from “all” to “10 of” – you could have created a new achievement called “Resisting the Corruption” that required “10 of” and then kept “Combating the Corruption” with “all” required as the second tier achievement for an additional 10 points. This is more work – we know it is, and we respect that it would require more development time to handle. But we deserve the time we’ve already invested to be respected as players. I worked really hard getting all of those corrupted monsters and I even made friends in Uldum doing it that I wouldn’t have met if I had only needed 10.
This is something being discussed a lot in the achievement discord today and it’s something people have big feelings about. Please consider this topic and think carefully on how you retroactively address acheivements in the future.