My time as a level 31 Gnome Warrior with Pigtails:

Stranglethorn Vale being camped by 7 level 70 horde for the better part of an hour.

My time on Draka as a level 13 Blood Elf Priest named Low:

"Why is my server down."
"Blizzard sucks."
"LOL WTF"
"Druids suck wtf"
"No u suck!"
"What? smurf you!"
"Dude, you both suck shut up"
"LOL"
"ROLF"
"LMAO"

I have also seen, on both horde and alliance:

Hunters that do not know how to use traps properly or at all.
Warlocks that think their voidwalker can tank endgame instances.
Mages specced as arcane thinking it is still the best dps spec available. (get over yourselves, fire is the best damage output.)
Warriors that don't know how to keep aggro on multiple targets.
PALADINS THAT DO NOT KNOW HOW TO KEEP AGGRO ON MULTIPLE TARGETS. THAT IS YOUR JOB.
Resto druids that use regrowth. No, you are a bad player. It is now more mana efficient but before the patch and the change, lifebloom was the best heal available to a druid.
Blood Elf Priests named Low.

Anyway, both sides have horrible players. Both sides have good players.

I will agree that, for some purposes, horde are better. Tauren Warriors make the best tanks because of one of their racials. Undead Spriest/Rogue are unstoppable in 2v2s because of one of their racials. Trolls provide insane dps because of one of their racials. Need I say more?

Anyway, Kael is a piece of cake one heroic. It's actually kinda pathetic. And I'm playing Low off and on. Just got back on after a little bit and I'm ready to level. You guys need to fix your schedule!