In previous MacBook models, ports were offered on both sides, but only because the motherboard spanned across the whole device. With the smaller motherboard on the new aluminum models, the designers would have been forced to spread the board across the whole device or connect a separate component group using ribbon cables.

Aside from the space allotted for the necessary DisplayPort and audio in/out, only enough room is left for three ports, argues Brockerhoff. Apple decided to integrate two USB ports and an Ethernet connection. Stacking the USB ports might have been impossible to fit within the case limits. He also notes that a Firewire connector requires the possible allocation of seven watts of energy, compared to 2.5 watts for the first USB port and just a half watt for the second.

Despite the outrage from users that require Firewire to run audio and video devices or troubleshoot with the target disk mode, the inclusion of just one USB port could have had the same effect. It is difficult to gauge the true reasons behind the decision to leave out Firewire, although the public reaction could have an impact on future designs.