Plus, if they continue adding this kind of job in the future -- how much of any given patch will be devoted to:

Blue Mage-only content
Beastmaster-only content
Puppetmaster-only content
Geomancer-only content

Can you imagine? "Sorry guys, we had to cut back to one expert dungeon per x.5 patch to make room for all the class-limited content" - it's a scary thought!