Originally Posted by
Arnorei
That's because more or less the Alliance now represents what Horde used to once.
Just think a bit, Horde was the underdog being pushed around but trying to do good and actually succeding in some places. They banded together and took anyone who needed help, even if they were a bit shady (forsaken) because they felt their wish to live and wanted to help them. They were united under a good leader, which, even though he made some mistakes from time to time, did them because he felt it was the right thing to do.
Now, think of the Alliance story since Cataclysm. At the banded together replace forsaken with worgen. Replace Thrall with Varian. Presto.
They also made the Horde as the villan. As an Alliance member, I don't really like this. I liked the lore because both factions were grey. I liked to be in a federation of countries, not the underdog led by some good leader who makes some mistakes. If I'd have wanted that, I'd have rolled Horde. And I'm sure most hordies don't like being the bad guys either now, since they wanted to play the role I said above.