I don’t think the writers intentionally bias either way.
I do think that they (deep down) view the Horde as kinda evil and the Alliance as mostly noble. (And yes, posters may posts with the Alliance meme that the Horde is evil and that the Alliance is good, I kinda think that mostly confirms they look at the world through “Alliance tinted eyes”.
I also think, when they think non-faction plot arc, they think Alliance lore.
I mean, even the biggest complain, Teldressil, was just part of the making the Alliance the good guys in BfA. I mean, the plot they always use is the bad guys strike a big blow, and the plucky heroes win against long odds. They just didn’t realize how different it is when, instead of someone like the Legion, the Horde plays the role of villain.