In an interview with Harry McCracken:
It’s always been about making the best Mac we know how. Among the many benefits are making it easy to use and affordable, with great features. This high level of integration is part of delivering on that.
And on Apple’s removal of the SuperDrive in modern Macs:
We find the things that have outlived their useful purpose. Our competitors are afraid to remove them. We try to find better solutions — our customers have given us a lot of trust.
If anyone is surprised the SuperDrive is dead, they haven’t been paying attention.