I think the main reason of hate against OR is that they have some players who really have a strong elitist asshole behaviour when dealing with players they don't know.
But if you were lucky to get to know some other members of OR first then you won't hate the guild or restrict the hate to the elitist asshole.
For example Golemus was very nice when playing with me, although I was pretty gimp when we first met.
And some weeks ago I joined an OR raid and Sakami was very kind and explained the labyrinth part of the first puzzles to me, because I never did that part before.
And they also have Mary, sorry don't remember her ingame names at the moment.
Youta was also nice in the last tr party I joined.
On the other hand... shatan was nicer before he joined OR. But he was also gimper before he joined OR... so maybe the elitist asshole behaviour correlates with the player skill level.
And big portion of the elitist asshole behaviour is probably the missing patience and easy freaking out over mistakes from other players. And sometimes mistakes happen even if you are not gimp.
But all and all... I think OR is less extreme in regard of elitist behaviour since several weeks/months(/years?) now.
Might be only my perception because my player skill might have increased so I am a bit more of an elitist asshole myself now.