Its an interesting question, I imagine you will get as many differing answers as people answering it, but I do like me these sort of questions, that are interesting and not bickering.
I play both. I always have. Waaaay back in the Dawns of WoW I played Alliance exclusively, but then I came up with a concept I really wanted to Roleplay with, that you just…couldn’t do on Alliance for reasons that will hopefully become apparent in my answer to your second question. Originally, Brigs here was going to be a Wildhammer Dwarf, and his Guild Gryphonriders, not Dragonhawk riders…
Its the concept. I had two things in mind when I made the character. I wanted them to be an aerial ace of their nation, and I wanted them to be like the Red Baron. An absolute patriot, who honours a worthy foe, but I needed something more than that. World War I was basically a land grab. Germany wasn’t ‘evil’, it was the ‘enemy’ (That isn’t me having a pop at Germany or calling Germans Evil, I have been there several times, and never found a more polite, hospitable and openly friendly people, I’m just trying to give context) World War II however, was, whilst from the average German soldier, just doing their duty, from the cold, dispassionate eyes of history, was them enabling a horrifically cruel, tyrannic regime reviled so much to this day, that I cannot even type their name on this forum without Blizzard censoring it.
And that’s what I wanted.
I wanted to play a character who is a genuinely good person, but working for an bad cause. I wanted to play a character who is absolutely implacable in aerial battle, and will shoot you down, whatever the cost, but the instant you have taken silk (Started parachuting to earth) will orbit you, make sure you land safely, offer medical attention if you have not, and whilst taking you prisoner, assuring you that you will not be tortured, but are his guest, and will live to see your friends and loved ones again.
It drives some Alliance people mental on Argent Dawn. Massive ferocity, dropping fire on people, then so insufferably ‘nice’ when the foe is vanquished. That’s what I wanted. Good people fighting for a Bad cause.
I presume you mean In Character? I mean Out of character I obviously don’t, I pretty much have an even split when it comes to characters.
In Character? No, Not Really.
Brigante doesn’t especially hate humans. He’s never going to be a fan of Jaina, and obviously he hated Arthas, but everyone did, but your average human footsoldier? Nope, not got a grudge. Remember he -was- and Alliance Dragonhawk rider for about 1,300 years.
Dwarves? No grudge there at all. Respect to the Wildhammer for their flying ability, but no grudge.
Gnomes? No grudge, he feels their pain, he too had to watch his land be invaded by an implacable foe, have to fight kith and kin who had ‘changed’, and lost his city. He has been lucky, the Blood Elves got half their city back…
He actually sees Gnomes as a force for good, on Azeroth.
Draenei. No Grudge. He was Shattered Sun Offensive, and fought on Quel’danas alongside Draenei, a Vindicator saving his life when he was shot down close to the Sunwell PLateau. There is an Alliance flier, character name Tibserai, a Draenei, in the skies they will try to kill each other, with absolute fury, she is a known ‘target’ for Brigante’s Escadrille (Squadron, aka the rest of the guild) but on the ground, in a neutral Booty Bay bar, they will quite happily drink together and chatter away like old friends.
Only Alliance he hates are the Silver Covenant, because he lost friends at Dalaran. And that’s just the Silver Covenent, not High Elves in general.