These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Lord of the Clans
Complete Monster: Blackmoore is an annoying little Smug Snake for most of the book, but by the end there's literally nothing redeemable about him.
In fairness, a lot of this is down to no one in his life ever showing him any respect despite all his efforts. Thrall later reflects on that Blackmoore did indeed make a particular effort to treat him as nicely as he knew how. It's just that he wasn't very good at it.
He does later concede that the last beating he gave Thrall might have been a little much.
The Dog Shot First: No. But below above why some see it that way. While the novel's depiction of humans is bad the novel is set after 2 wars the Orcs started winning the first one and being responsible for mass murder and enslavement of the intelligent dragons. Even the current retcon paints the Orcs as invading Azeroth because they themselves very nearly destroyed their own world.
Moral Event Horizon: When exactly Blackmoore crosses this is probably grounds for a full internet discussion since there's so many damn things to choose from.
Undoubtedly, the ultimate crowning moment of evil is murdering Taretha and throwing down her severed head just to screw with Thrall's head. Granted, she had betrayed him, but throwing her head to Thrall was unnecessary, and refusing an opportunity to surrender cost the lives of more than a few of Durnholde's defenders.
Narm: Some might find Christie Golden's prose to be replete with this. But the manner in which the Orcs talk is a more particular example of this. Aside from that, Draka spitting in Durotan's face and how we're supposed to take that as being an expression of their mutual love is... well.
Never Live It Down: Even though there had to multiple prisons for the imprisoned Orc's armies this novel's depiction of a single camp is often cited as why humans are the real monsters in Warcraft, ignoring that even with the Retcons, the orcs still tried to exterminate them.
What an Idiot: Explain to me your reasons for taking your wife and child with you on that perilous journey to Doomhammer, Durotan? Needless to say, this act leads to his son being enslaved by humans.