I am well aware of that, and I have made this argument because the premise of the opposing argument is essentially: If they're wearable they should be transmogifiable, and that it is a "punch in the face" to put this exception in place for the The Warglaives. My argument simply explains the rationale behind the exception.
You're arguing false equivalence here. Also I've already addressed this point.
If lore and class fantasy was of paramount importance, then yes, they'd have to turn The Warglaives into warglaives and make them unusable for everyone except Demon Hunters. But unlike not making them transmogrifiable for a bunch of classes for whom they were never transmogrifiable to start with, taking them away from classes that could in the past equip them, and for which a number of players have invested a significant amount of time and effort to do just that, would actually have warranted the label of "punch in the face".
There is world of difference between not giving a bunch of players something that they want but never actually had, and taking away something that they worked for.
As stated, I agree that Blizzard's stated reason is silly and poorly worded. Because really, it's about a whole lot more than just invalidating effort - there could be other ways of addressing that, for example allowing the other classes to do that quest. What Blizzard failed to state was the underlying reason why the xmog was only ever available to DH's, and that is that allowing it for other classes just doesn't make any sense and would detract from the idea of class identity.
Really? You're just trying to use whataboutism fallacy to justify your argument.
Can DH's xmog Fangs of the Father? No. Can Hunters use Shadowmourne? No (hell, hunters can't even equip the original Warglaives even though they're swords). There is a long list of special things reserved for specific classes.
It's one thing arguing for something for a class which makes sense based on the class fantasy. I am sorry, but to me, this just really comes across as jealous whining that it's not fair that xyz class doesn't get to have something that another class has.
If imitating Illidan is the thing you want to do, then roll a DH. I can promise you right now that the idea of being one of a slew of rogues and warriors walking around equipped with a pair of warglaives is really not as you think it will be. In fact it will look outright silly.