Having a reasonable explanation doesn’t justify the behaviour. It is merely an explanation. Sitting down with someone and finding out the story behind their behaviour can help reach a common ground with one another however.
Daelin chasing after Thrall’s peaceful Horde with the sole purpose to wipe the orcish race and its allies off the face of Azeroth isn’t right but we, the readers, and many of the characters in that universe can understand why he acted as he did. Jaina tried to reason with him and it unfortunately didn’t work.
Zul’jin is lauded as a great character despite his fanatical hatred of the elves and the fact that he wanted to see to every elven man, woman, and child dead and Silvermoon burnt to the ground. When the Scourge rampaged through Eversong Woods and decimated 90% of the population Zul’jin’s immediate reaction was to attack the elves when they were at their lowest.
By our real life standards his actions were nothing short of sociopathic but from the perspective of the Amani, a race that had everything taken from them by the arrogant elves who believed they could do whatever they wanted because magic, Zul’jin was a cunning warlord and a hero.
It isn’t easy if it’s written well and in a way that invites legitimate discussion around said character. Anyone can fart out a Tesco Great Value Garithos and call it a day but it’s not going to be a tasteful or objective representation of the subject.
To bring up concrete examples, look at William Ford in 12 Years a Slave. A man of faith and by all accounts a man regarded as kindhearted, humble, and a devout Christian by not only his peers but his slave, the author, as well. Though he was partly a product of his time he still erroneously believed that slavery was right or at the very least necessary.
He treats his slaves much kinder than other owners but he still views them as lesser simply due to their ethnicity and exploits their labour. He might not be actively enslaving anyone but he is complicit in the continuation of the practice by purchasing, owning, and selling people.
Scarlet O’Hara from Gone with the Wind can be seen both as a misogynistic caricature of women and as a strong feminist icon. She is spoiled, vain, very materialistic, knowingly acts like an airheaded bimbo to manipulate men, uses men solely for their wealth or as a tool of petty revenge, and is pre-occupied with nothing but banging one particular person. It reads almost like an incel manifesto, right?
Yet she is also clever and resilient, cares greatly about her family, refuses to adhere to the strict societal standards set for women of her time and status, and is the only one in her village to not only survive the economical collapse that followed the Civil War but protect others from destitution as well. Through the course of the book she becomes more ruthless and hardens her heart in order to see her plans through because many depend on her.
Those two are characters that both engage in problematic thinking and behaviour, to put it lightly. Yet they aren’t just a sum of their faults. They are well-rounded characters who also happen to be very bad in some way.
Contrast that with the average racist / sexist / something-phobic character on Argent Dawn and you’ll see what I mean. It also doesn’t help that due to the two party consent nature of roleplay these sort of characters rarely develop past their schtick but also do not face consequences for it.
Garithos, for all his faults, ended up getting his rightful comeuppance before he wore out his welcome. Had Blizzard Blizzard writers decided to let him somehow outsmart Sylvanas and keep running the show he would have come to be regarded like Ronin, with players wishing for him to be iced.
I don’t roleplay such heavily flawed characters because I don’t think they work well in the context of this game and its roleplay scene. In my opinion the Dungeons & Dragons universe is better suited for exploring those kind of concepts in a serious manner.
Also, no, this isn’t to stay that the WoW roleplaying community is inferior but that the MMO has been made to cater to more general audiences and the playerbase reflects that. Trying to handle certain topics with maturity and objectivity is going to be difficult if half your interactions are with people still in their teens and early twenties, who describe characters such as Garithos or Garrosh as poggers and based.
I also do not think I’m a particularly good roleplayer myself. Enjoy writing more than anything. I do not tackle certain subjects at all however, in any setting, because I know that my own personal experiences cloud my judgement too much to be able to write objectively about them.