It's really not usual at all especially for devices that are not required to be connected to each other or span different generations of Macs. The AirPort has

It's really not usual at all especially for devices that are not required to be connected to each other or span different generations of Macs. The AirPort has never come with an Ethernet cable The iPod never shipped with both FireWire and USB to 30 pin cables The ThunderBolt Display was incompatible with Macs without ThunderBolt ports The 30" Cinema display was only compatible with the Mac Pro when it launched and later required adapters (not included) to be used on other Macs The original iPhone's recessed headphone jack required an adapter to use older iPod headphones The first generation of Apple USB mice/keyboards did not come with an ADB adapter