This is because your device is either required to have a MFI chip in it, or you have a common device already in the home with a MFI chip that it can communicate

This is because your device is either required to have a MFI chip in it, or you have a common device already in the home with a MFI chip that it can communicate with. My company was one of the first to have a HomeKit thermostat, and the biggest barrier was the hardware requirement.