You make it sound if it was just a matter of changing the ADE file.
That's not so easy, because the whole background changed, taxiways changed, several areas are being rebuilt, and some are still in progress. Lot of work, to update a scenery which was initially made 10 years ago. Simply not worth the effort
In addition to that, if we had to support FSX too, we would have to dumb down the P3D4 version, and this is simply not acceptable, considering the majority is clearly on P3D4 right now.
