If you know anything about this exploit, you know that no fix for it is going to be easy. It's built into a basic function of the game, so to fix it they either a.) have to fix that feature of the game or b.) have to write code to identify 8+ man groups in WZ and deal with them. Either fix is going to take a substantial amount of time, and the game's only been out for a total of 2 months. It needs to be fixed, it needs to be a priority, but you make it sound like the fix would take 3 lines of code. That simply isn't the case.
There really is no defense for Ilum, it's horrible. However, at least on my server, there are some times when both factions are out in force and those times are some of the most fun I've had in the game so far. If they could just find a way to make that happen more than one or two hours a day than I would be more than happy to keep Ilum. The devs have already made changes to Ilum, though, and even if they were the wrong changes, it at least shows you that they do know there is a problem and they're trying to fix it. Scrapping Ilum, at this point, is really not an option. What are they gonna do, have no open world PvP for 6 months while they build a new system?