Except no one here seems to have a firm answer on why it is not bookable online while BA and AB flies to Abu Dhabi daily from Europe.
If it is a regional thing, then why Kuwait, Bahrain, Dubai and Doha are all bookable.
If it is a country thing, then why Dubai is bookable (OK, EK flies to there but it is not an explanation rather than pointing out to the fact like I have pointed out the fact that you can not book Abu Dhabi online).
If it is a technological thing, nobody would believe that you could simply not put Abu Dhabi in the system.
If it is an airline thing, then why 99% of BA and more than 90% of AB destinations are bookable online? And EK do have a Abu Dhabi destination although it is bus.
I am just trying to make sense of a little unusual thing.