Well, actually, have you seen this forum in the last few month? Hordes are going nuts at the the prospect that they are forced into peace with the Alliance for an expansion. The amount of people demanding exactly what @
Feanoro describes is not as small as you make it sound like.
The problem is that the playerbase is completely divided. Some people play Horde because they want to be the noble savages, or the outcasts trying to overcome the prejudice of others. Other people want to be the bad guys, genocial murderers that just want to have war because slaughtering humans is fun.
Somehow Blizzard is forced to please both of these sides somehow, hence why the Horde keeps going from chaotic good to chaotic bad in the span of a few expansions and since consequences cannot ever fully affect a player faction (i.e. it cannot be wiped out, no matter how much it deserves it) there is scapegoats in place, like Garrosh and Sylvanas.
This is why I fully expect to see another insane warchief (maybe not by that title) in 11.0 or so that will again turn the Horde into a tool for genocide, because otherwise the part of the playerbase that WANTS this will leave.
So in essence yes, the Horde Fans ARE forcing Blizz to write this stuff.