I notice that once again you retreat from offering any evidence and instead retort with the fallacy that this debate is 100% subjective.
No, it is not. There is a canonical, de facto answer.
For your benefit, just SOME of the canonical, objective evidence.
'Date: 29 September 2005 WoW Forums Post by Caydiem
There are still some High Elves in the land, but the majority of those once known as the Quel'dorei no longer fit the bill of "High Elf".
Your comparison with Gnomeregan is a logical conclusion to draw, but incorrect. The Gnomes managed to evacuate a good percentage of their people from their home as it was corrupted from within. Ironforge was close by; they were able to save a good number of their people. Naturally they were indebted to the
Dwarves and, by extension, the Alliance, so they fight for their cause.
The High Elves had less of a chance to flee, as they were surrounded by the vast bulk of the Scourge army as they pressed in and destroyed the Sunwell. Still, some survived, certainly enough to show a presence, right?
And so they did after the destruction of Quel'thalas, fighting for the Alliance, but with the destruction of the Sunwell they found an ever-increasing need, an addiction, for magical power. The remaining Elves were placed under the command of a man named Garithos, who was grossly intolerant of other races and drove the Elves into near-suicidal situations in the hopes they would no longer be his problem.
These remnants of the High Elves -- named Blood Elves in remembrance of their people -- were not stupid, and the commands from their "Alliance" became more and more ludicrous. It was only through the help of the Naga that they were able to survive these grim tasks; time and again, they appeared to aid Prince Kael'thas and his men. The Blood Elves came to realize they could no longer trust in the Alliance. When the offer was extended to join the Naga in service of Illidan Stormrage -- and perhaps find a cure to their addiction to magic -- Kael took it, leaving the Alliance behind.
In short, High Elves are not playable because there are very few true "High Elves" left -- far less so than Gnomes. While there are Blood Elves in much larger supply, they are busy with other pursuits alongside Illidan. You'd certainly not see them fighting side by side with the Alliance anytime soon, not after such betrayal.'
AND
From the Warcraft Encyclopedia
In consequence, there are so few high elves left on Azeroth today that they cannot be considered a race in anything other than the biological sense.
And confirmation in a tweet that the Warcraft Encyclopedia is still canon by Blizzard historian Loreology aka Sean Copeland
'@Loreology @Bashiok Warcraft Encyclopedia was disappeared long time, does it means the history information from encyclopedia was abolished? @GregoryMoonkin @Bashiok Not at all. While there might be some updates to it, its disappearance doesn't mean it's no longer canonical. '
A link to who Sean Copeland is...
https://wow.gamepedia.com/Sean_Copeland
And of course the infamous video where Ion Hazzikostas, the man who has been through a period of overseeing which allied races would be added and which would not, who has likely thought a lot more about Elves of all descriptions in the past eighteen months a lot more than even we have, giving his thoughts on the matter.
And of course, the TWO interviews given in a post Void Elf world (for those who persist in trying to argue that Allied races open the door to playable High Elves when they are the only ones explicitly ruled out).
Canonically, there are two few High Elves to justify them being an Allied race.
From out of game interviews, we know the developers believe that Blood Elves are High Elves, that High Elves are already playable and that there is no need to replicate the same race on the other faction.
The assertion that Blood Elves are Hight Elves is backed up by every source in game and out.
As I said, an objective answer.
Pretending this debate is one hundred percent subjective is nothing more than an attempt to move it onto ground where the Pro High Elf position is equal to the Anti High Elf position. That is demonstrably not the case.
You can't handicap the truth, unfortunate for the pro High Elf point of view.
The subjective pro High Elf point of view cannot compete with the objective basis of the Anti High Elf position. This is why the subjective pro High Elf argument always, always, always boils down to the same tired old position.
That if they complain long enough and loudly enough, Blizzard will cave and retcon the game to give them what they want.