Khurt, my understanding it has to do with the hardware requirements for some of the features. My mid 2011 iMac does not have bluetooth 4.0 LE capabilities which is needed for some of the features. With the sms and phone calls Apple is not using bluetooth, but everything is happening over the wifi, hence the need to be on the same network. Not that I am complaining, as it is the sms and phone call features that I like the best and use almost everyday.