I do think some of what you’re saying here is inherently true and acknowledged. The part I would disagree with is “the” bad guys.
The issue is that current writing has basically portrayed the Alliance as the bastion of morality and virtue. They are basically always in the right and justified and until they are given some level of “badness” the Horde will always fail in the narrative.
I don’t want the Alliance to have to spend a decade of expansions that basically just tell you “you picked the wrong faction!” - that’s awful. Plus if they did that for real then the Night Elf folks would go berserk because the last decade has been pretty good for them compared to other races (pre-BfA) and some of them feel they’ve been victims since … well however long they’ve been alive. But I do think the Alliance has to have some elements introduced in some way that allow them to be imperfect.
Some of these attempts may be heavy handed and it’s partly because there’s a lot to reverse. I think there is a decent amount of debate as to whether it’s better (or even reasonable) to have the Alliance just jump full evil - torturing Vulpera babies, whatever - or have a more prolonged lesser “evil.”
I can’t speak for everyone here but the end result I do want is that both factions (in general) try to be heroic - but they will disagree on what the best choices are. There may still be some bad actors but they won’t be what defines the factions.
I believe in another thread there was a reference to “Wolverine vs Captain America” or something as a goal Blizzard had promoted. The Horde would be more likely to view the ends justify the means, willing to kill their own people if it meant the death of - pick a colossal supervillain - because that would save more lives down the road. The Alliance might not be willing to do that. Assuming the Culling of Stratholme was successful - it would be something the Horde would advocate, while the Alliance might want to try to separate folks and see who develops symptoms etc. I think there are plenty of ways both sides can face the same problem and take actions their players at least can see a justification for. The problem is the current iteration of the Alliance has no room for that - they are portrayed as the bastion of morality and virtue while the Horde are generally shown as savages who would do well to learn from the alliance. If that doesn’t change entirely, then the Horde will always fail in storylines.