Even the names of the factions reflect this, a bit.
An “Alliance” is when you get a group of people with like-minded ideas and goals working together.
A “Horde” is when you have a group of people that happen to be doing the same thing.
Back during launch, one thing you’ll notice is that all of the Alliance factions were friendly to each other. This wasn’t the case with the Horde (Undercity is neutral).
What I think - and this is purely conjecture - is that the idea and aesthetic of the Horde tended to attract a certain type of player. The underdog feeling, blood and thunder kind. This was cultivated early on by Blizzard, because that makes sense when you have a successful product.
But over time, it went from just being “we want to feel like an underdog with dignity, ready to protect and fight for things” to “death for the death god”. This was reflected both in the story and - I hesitate to say - some of the actions of the playerbase.
I really wish I could find the interview or article, because I am positive I heard Blizzard mentioning one reason Garrosh was so…Garroshy is because he was supposed to represent what the developers were seeing with the player base. People were moving away from the relatively peaceful unless provoked Thrall to blood and thunder Garrosh.
But at that point, tribalism was in full effect. What, you want to be like those Alliance cowards? No, lean in to it. People a little surprised that so many people were siding with “Death to all things” Sylvanas wouldn’t have been that surprised if they had seen how quickly people lined up with Garrosh back in the day.
More conjecture? The rumor mill is that a lot of the developers and writers tend to play Horde characters. Which is fine, it’s just…without people in there who mainly play Alliance characters, or people who alternate between the two? You’re not gonna get met with too many people who might slow your proverbial roll. You’re going to keep looking at things through that same lens, and then we end up with surprise that people don’t view your night elf genocide thing as “That’s pretty epic, but we can just move on” or “they’ll surely be okay with this”.
I mean…this got so bad that people are actually doubting Saurfang. From launch until…well, this current expansion? That man was venerated, in part because he actually was telling people not to be a part of the old ways of the Horde.
I don’t know. They wrote themselves into a corner, and I really want to think their solution isn’t going to be to try to break through the wall and see if they can go farther in the direction of the corner.