As an opposing view, LDoNs give smaller groups (and in theory, smaller servers) something to do without ruining the zones that do require larger groups or raids. I was a big fan of LDoN because of 2 things; 1) it introduced instancing, so that asshat level 65 couldn't come steal my goodies I camped 900 hours for, and 2) me and my very busy RL mates could dash into the game, take an adventure, knock it out, and still have time for dinner and a movie. Shrug. It's all about perspective.
As for priority in emulation, I agree it is not the top-most priority. That's why >I< have been looking into it - a non-developer who can barely spell C++. And I have only harassed Core Dev 2 times about it
However, I feel that if this gets some attention, and some architecture gets implemented to support not only adventures, but tasks and missions, it would open the door to many of the newer features you do like - like DoN Missions. It seems basically the same. Grab a mission, complete it, get crystals. How is that any different than LDoN points?
As for the zones all looking the same... that's called Themes, silly. But yes, after 200 of them, they started to rake on ones nerves. However, imo, missions and tasks are no less redundant and boring after awhile. They all still need work, and someone should step up, git er dun.