There are two points to this SIM, and dedicating it to a carrier only negates one. This SIM still removes the requirement to either purchase a carrier specific

There are two points to this SIM, and dedicating it to a carrier only negates one. This SIM still removes the requirement to either purchase a carrier specific SIM before first using the device, or have Apple stock devices with the various manufacturer's SIMs preinstalled. Making a customer poke their new device with a paperclip and load a SIM is not very Applelike.