I think what makes durability different from other features is that it's mandatory among everyone. Having the freedom of choice makes a game more versatile, especially an MMORPG, and AQ3D hasn't been too open to that concept, so that'd be the first thing to consider. Like a casual player isn't going to be required to farm Midas' Curse or farm for things in any optional release... they can just stick to the story, or make a choice on what they want to do. Even if a durability system could work out, I'd like to see the freedom of choice be prioritized so then the game doesn't weigh itself down by less exciting things. Many players were already turned away when AE introduced class ranks, because they already had to grind for tokens to earn the classes in the first place which they though was enough, and some new players couldn't really adapt to the change. The original point I made about making gold sinks catered to hardcore players is that the hardcore players often accumulate too much gold that they don't have much use out of, and incentivizing them by letting them spend gold to save time of things opens up that freedom of choice.