A) This is game-breaking for a server that promissed a so close vanilla experience, althrough it has the innkeeper thing and some little changes, but at least this innkeeper thing got announced before the release. I wouldn't hype myself about kronos so much if they announced this game-breaking feature before releasing the server... Perhaps I would even bear it, but since they addopted this terrible casual measure after releasing the server, we, hardcore players are feeling like we've got deceived.
B) It isn't purely aestethic, it's a core part of the game, seeing an human riding a kodo makes me think I'm playing just another messed up private server like the others I played and quitted before.
An USA soldier wouldn't scream ALLAHU AKBAR in the battlefield unless he wanna get killed by his allies, the same goes to an orc which would get murdered if he were riding an alliance goat. This crossfaction mount exploit is much more than an aestethic issue, it's a proof that the casuals can destroy this server just like they did with the original servers. We must fight against those casual players and start the purification of this server if we don't wanna end like the blizzard servers. Just take a look at how the casual players destroyed WOD and how they're getting exploited with the Legion xpac which is nothing more than WOD cutted content.
As if those casual players weren't satisfied of ruining the blizzard servers, now they are destroying kronos-wow too, casual players couldn't handle a true world of warcraft, so they can't go to a server that is getting well-known because some hardcore players are praising it, so they must ruin whatever we, hardcore players, make famous.