One of the Jobs' supporting argument about integrated approach is that the tight control is what enables them to make the computers "smooth".
While there is some amount of truth in that, the other side of it is that it's just marketing cover for Jobs' control freak nature more than anything else - why is Springboard crashing on me 5 times a day if control makes it possible to have great user experience and Apple has full control? Why for another example Apple is letting me install apps that crash routinely if they claim they locked down so they can control the quality of user experience?
One of the "revelations" in the biography is that Tim Cook said to Jobs during the Antennagate that there is general impression that Apple is becoming another Microsoft - complacent and arrogant. That gives me some hope that post Jobs there might be at least a pause to Apple's nonsensical lock down policies.