Their goal is to have Draenor feel like a very dangerous place. The comparison Ghostcrawler used was Fel Reavers in Outland, only instead of Fel Reavers there will be giant Gronn like the ones seen in the Warlords of Draenor trailer. Situations like that are much less dangerous when you can just hop on your drake and fly away.
The topic comes up at 58:30 in the podcast for those interested, but the entire episode is worth a listen.
Filed under: BlizzCon