Garrosh was a dictator, not one dictator in actual human history has been a good guy, horde hasn't seen honor since they left Draenor.
Actual refugees don't invade other countries. They co-exist if they are taken in.
Orcs came like "This is our land now!" not really asking eventually forming the horde to oppose, not to co-exist.
Sure alliance didn't take them in, but would you ask a bunch people breaking in to your house like "welcome, please take a seat and eat my lunch".
Even if you're being brainwashed by a dictator whether that's Garrosh or Gul'dan back in the day, if one can't tell the difference of a invasion or being a refugee, when being part of one, bad news is, one might be a bad guy, an uneducated one, but a bad guy non the less.