What is wrong with raiding, 10 vs 25 man, in Cataclysm

Ok let me talk before you start throwing things.

Raiding in Wrath of the Lich King (henceforth: Wrath) built upon the lessons learned by Blizzard in tBC.
They noticed that people loved the option of going with 10 man raids.
They also noticed that there was a huge problem with raiding in tBC. That was that you basically had to do every raid after the other, starting with the oldest easiest ones, in order for you to get to the gear you needed for the later raids.
If you wanted to do Sunwell you had to have done everything before Sunwell for you to have any sort of decent gear basically.

So enter wrath.
In wrath every raid had the option to go either 10 or 25 man. Great, everyone can choose what to go for. Current gear could be gotten through heroic dungeons and tokens.
The problem here was that 25 man raids where harder than their 10 man counterparts, another issue was that every raid had separate achivements for 10 and 25 man.
To clarify: Every raid achivement had 2 versions (some exceptions).

So people started thinking that 25 man was the more hardcore way of raiding, and Blizzard reinforced this by tieing certain quests (like Shadowmourne) to "only 25 man" and most of all through loot which was much better on 25 man.

So; Cataclysm.
In Cataclysm Blizzard wanted to remove any sort of "This way is the real way to raid" by having 10 and 25 man raids share everything. Loot, achivements, lockouts and difficulty.

My issue is this.
10 man is very different from 25 man! Now I'm not saying that 25 man is always harder or vice versa, but they are very different. Some bosses are easier on a certain raidsize, this is a fact. The problem is not that I want to go back to the wrath system of doing things, the problem is that I don't get recognition for what I have done.

Blizzard turned away from using separate achivements for the different raidsizes because they are supposed to be equaly hard now. They are not.
You tell me that Nefarian on 10 man is as hard as it is on 25 man with a strait face.

I want Blizzard to reintroduce separate achivements for killing Cataclysm bosses.
I don't want the metas to go that way though mind you, I don't care about them. I just want to have a separate achivement for Bastion of Twilight 10 man and Bastion of Twilight 25 man for example. That's all.