In the few MMO's that I have played I have always enjoyed playing the odd man out.  I think playing a human in any RPG setting is the vanilla of the gaming experience.  I played a Taru Taru on FFXI, a troll in Camelot, and mostly a gnome when WoW first came out(with a bit of Nightelf for the Druid experience).    When Burning Crusade came out I resisted renewing WoW, but I eventually gave in and had to level me a 70 blueboy shammy.  So I got my 70 and I was done with WoW, in my mind, until the Litch King shows his mostly obscured face.

Then the fellow who first got me into Camelot, FFXI, and tried to get me hooked on Eve said he wanted to play WoW again.  I was elated, my inner self-satisfied jerk was grinning from ear to ear about how I could lord my Level 70 over him and be like the big brother figure.  And I think he realized it, so he said he wanted to play Horde.

....All I could think was "Holy Biscuits, do I really want to start the grind over again?"  Even worse, I didn't know where all the low to mid-level quests were, like with most of the Alliance areas. 

After a few moments of agonizing over this, realization hit hard enough to crit.  "It would be a totally fresh experience."  I would have no long-time high level allies, everything would be fairly new to me, and I could see places that came out since BC that were completely foreign to me.  It was almost like a new expansion, just for me!

I had played a tiny bit of Horde before, mostly undead, so I had seen the usual haunts.  But it was never a committed effort, I always knew that I would abandon the character and go back to "safe ol' Alliance".  I was also apprehensive about the players I would be allying myself with.  Every Alliance faithful knows that the Horde is jam packed with foulmouth, rude teenagers who steal objectives, resources, and PK at the slightest provocation. 

Then I found out, Alliance do the same thing.  Though I have meet one or two rude teenagers since my changeover.  I can hardly hold it against an entire faction.

WoW is an expansive and deep fiction created through many means of story telling.  And despite the polish and connective nature of the Alliance, it is also fairly bland when put in to comparison with the Horde.  That is not to say the Alliance doesn't have it's fare share of depth and drama, but it doesn't wear it on it's sleeve like the Horde does.

I have found that the reason you can find so many loyal Horde players is that most everything they scripted for Horde players is designed to pander to our natural sense to belong.  These Horde NPC's and other players need you and value your participation.  It feels like if you and your cohorts don't band together the world as you know it will shatter.  It feels like your efforts are a bid in the fight for survival.  Where as in the Alliance, it mostly feels like anything you do will just maintain the status-quo.  

If you take that point, mutual survival paired with the respect that comes from watching each others' backs, you can start to get the underlying theme of the Horde. 

The Alliance is banded together, seemingly because all the races in the Alliance are good, fine and none-to-ugly.  I am sure there is an explanation with more details, but I doubt that anyone needed any more reason than that. 

When I started my Blood Elf Pally I was consumed by the need to know why the Blood Elves would ally themselves with the Horde.  And to my delight I found out that there wasn't one overbearing reason, but 20 smaller reasons, all well documented and evident in several sequences in the game.  And it drew me in more.

I will probably still play my Blue Shammy Man from time to time, especially once I get my Pally to 70 and nothing really new awaits me with that character.  But one underlying lesson resonates from this whole experience with me.  That lesson is, give the opposite faction a fair try.  Create a serious character you might want to play, in a class that you may not considered playing before.  Then play it seriously for a week, see if you don't fall in love all over again. 

For anyone who is wondering what my character's name is, and what server they are on, I am leaving that out.  I would rather not be targeted by Allience every moment of my playtime, at least until I am 70 with the most pimped out Ret Pally armor in existance.