imo the Draenei are some of the BIGGEST idiots as a race. They were chased by the Burning Legion for eons. When they reach a new home they find it lacking demonic taint and its people (the orcs mainly) not using arcane powers. So what do these Draenei do? Use arcane power. This brought the Burning Legion to Draenor etc,etc, etc....so next time you hear a Draenei blame an orc, you should know that the Burning Legion would have ignored the orcs for a very long time

@Jamz

There are a couple of problems with this. The Draenei and Eredar are good at arcane magic thats sure, because that was the reason Sargeras found them in Argus at the first place. But after converting most of the people to the Burning Legion, they started to use the light.

Most of the Draenei you see are Vindicators (Paladins) and Priests. They obviously know Arcane magic, but they mostly use the Light and follow the Naaru. They shield their cities from the eyes of the Burning Legion.

The reason the Burning Legion finds them is because the Eredar and Kil'Jaiden considers Velen and the Draenei as traitors, and they actively searching for them. So they will always be found sooner or later, no matter what they do. Actually they were able to hide in Draenor for a long time.