[sneak]

Adding a USB-to-3.5mm audio interface is $10. "Those people" spending several grand on a new laptop can make their audio-out cable 5" longer.

Apple still cares about them, obviously, and will happily sell them computers, which they will happily still buy.

[cr1895]

Pro audio people probably won't be using a cheap in-line DAC.

[nileshtrivedi]

USB supports analog I/O so DAC could well be on board.