This is definitely not a dead horse - has a very real purpose. To preserve maximal challenges for those of us who play the game to the fullest potential and want to be pushed to the limits of performance. That's absolutely a fun draw to any MMO, thus is a very large draw to raiders' subscriptions.
Bioware is driving away subscriptions by nerfing..and people are going back to WoW or will be going to Final Fantasy XIV 2.0 over this.
I personally will lose complete interest in the game if Nightmare fights all become carebear mode, thus I am unhappy with any nerf to a fight which has been killed ever by anyone within the first month or so.
You don't appear to realise how few people are like you. There are 12 confirmed kills of DG. That's it. That's not even 100 players. No company that wants to stay in business is going to create content that only 100 people ever see (ie everything past DG).
The fight is still far beyond the capabilities of at least 95% of the playerbase. It is hard by any reasonable definition of the word. If you don't find it hard, then you're just very unusual.