Agree with Alanid. The Aldor still haven't entirely put the Scryers out of their minds, and with an Outland orc with heavy racial bias taking the reigns in Durotar, it could respark the anger within Draenei. After all, the Horde's peaceniks, the Tauren, may be going on the warpath if a certain tribe gets its way; who is to say the Draenei can't do the same? (Actually, it would be kind of hilarious if the Draenei become zealots of the Light, deciding everyone should be put to the flame for the most minor offenses -- see Warhammer 40K's Inquisition).

This is a longshot - but it could be possible - that by moving to Azeroth, and having to deal with warlocks and shadow priests (whose power "breaks down" or mutates the draenei), along with the corruptions of the Old Gods, Burning Legion and the Scourge, the Draenei's connection with the light is beginning to dim. And thus, they are changing.

Another longshot to consider: Velen's just a heartbeat away from changing the entire Draenei outlook. Like the Tauren or Orcs, the Draenei could suffer a change at the top that alters the race's entire outlook and attitude. The only other Draenei with similar views is a broken (the shaman trainer, if I remember), and most of the Draenei still haven't shaken off their distaste of their stricken brethren.