It is a delicate difference, and maybe therefore, a wee bit difficult to point out.
But I will try.
When one starts leveling a Worgen, one is being plunged into the Worgen capital that is in great unrest because some of its citizens are suffering the curse. The whole starting experience in leveling that race is about inner conflict, flight, confrontation and eventual rescue, i.e. leaving a “city in ruins” behind. The Silverpine questline (which is a really interesting one) is hinting at the desolate “Worgen situation”. So a Worgen racial player is from the beginning confronted with the fact that he - has no home - other than the refuge within the greater Alliance (by residing at another race’s capital). There is no ''capital bonding" in a sense that other racials experience their leveling which takes them right up to 110. The Worgen, the Gnomes, (to some extent even the Goblins), the Void Elves, the Draenei and the Darkspear all have to make do with ''refuge/temporarily homes away from their original (wholesome) homes/capitals.
What I am driving at is the fact that when you level these racials there is no capital bonding from the start other than the affinity for their present abode.
On a completely different level you have racial players leveling at UC and Teldrassil. These are ‘‘functioning’’ capitals and they grow on you as you level up to 110. These capitals are part of your racial identity - there are no other homes to go to.
So, by destroying these and giving nothing in return (remember that the Forsaken and the Night Elves who are living like squatters in their faction territory have no ‘‘temporary home’’ like the Draenei, and Darkspear, for example.
Furthermore, the Worgen and the Forsaken have, at least, a remote hope that someday they will return to their initial, original capitals.
The Night Elves have nothing of the above. And that is the crucial, stark difference. That is a major reason, why there is such an outrage in the first place. What Blizzard have done is the most callous, disrespectful and idiotic move they could have done as an enterprise set on making money. It is totally unprofessional to alienate your customers.
So, while it may be a nerving experience for some that these complaints are still on-going, view the matter from this side of the argument and you may come to see that Night Elf main players really have a case…
… and, I rest mine
Edit:
And it could have been so simple for Blizzard to cushion the blow to their player base by offering, at least, a temporary home for the Forsaken and the Night Elves. Have it known (especially when BfA began) that after the catastrophe the majority of Forsaken found refuge at the Scarlet Monastery, for example, and the Night Elves in Eldre’Thalas (and finally granting Shandris Feathermoon the victory over the Ogres there). The outcry would have been far less and Blizzard would have been able to contain an affinity to the game, despite the havoc. But what do they do? What are they still not prepared to do? It is mind boggling to see them at work!