Islam is trying to do something great, it is his job to beat the guy across the cage in a fist fight, it is not his responsibility to maintain THAT GUY''S perceived greatness.
Islam gave Volk the opportunity TWICE to attempt to achieve double champ status. Islam now has more(or equal) title defenses than Volk did at that time.
It is his turn to attempt greatness.
If anything things are finally right in the world that the fighter with the greater accomplishments is the one getting the better opportunity and the guy with less accomplishments is the one taking the risk with less reward.
Islam with 5 title fight wins getting a shot to dethrone the guy with 1 title win makes much more sense than the guy with 1 title defense getting the THIRD time Islam had to put his own belt up.