Is prejudice towards certain races in Warcraft justifiable?

I have seen this take in arguments at times, that the way some races are depicted as being prone to being problematic makes any general negative sentiment towards them to be logical.

Examples I see that are the most popular:
Orcs - Theramore's destruction/the Iron Horde would prove Orcs to have a tendency for being destructive and dangerous. It has been a while, but I think Jaina is said to agree with her father Daelin about Orc and Horde extermination after Theramore.
Trolls - Trolls are usually drawn to dark magic and "barbarism" and tend to cause problems often.
Forsaken - Arguments often revolve around the Wrathgate, plague, Sylvanas' betrayal, etc.

Notably, there are exceptions to all of those in the way of opposition to these actions, but the tendency for problems in certain races appears to be a bit clear. At the same time, there are always exceptions as some members of the races previously mentioned were against the actions the arguments tend to point out.

What do you think?