Because it's audacious?
As a lapsed Audaxer who's done some of the big rides [BCM/LEL/PBP] the concept of Everesting is an interesting one.
It's probably easier to ride an Audax that does 8848m+ climbing than it is to Everest a single climb to cover the same altitude gain.
Let's put it this way:-
If you don't get that then, in my opinion, I don't think you don't really get what Audaxing is about.
[ I didn't when I first started Audaxing. I do now. ]
It's not about what it's easy and what it's hard and it's not even about whether it is Audax or it is not, clearly it is not, but that is immaterial, we had cover prictures of people touring around the world, and that was great.
I am not even saying that Everesting is not interesting, I thought about going up and down Bwlch-Y-Groes myself.
What I am saying is that IT IS NOT a form of long distance cycling, simply because you are not going very far at all and you don't have to face the challenges of long distance cycling, here's a few...
-being stranded with a mechanical a long way from any help
-having to negotiate foul weather a very long way from any shelter
-navigating your way to the next control/village/refuge for the night
-managing your time so that you get to X before the control closes/before it gets dark/before the forecasted storm approaches
-making sure you carry enough food and water until the next control/village/gas station
Since AUK and therefore Arrivee promotes long distance cyling (which is all of the above and more), which is our very own USP, why should it promote Everesting, which is going up and down a mile stretch of road n times and is none of the above?