GM has some of the best software developers in the world - the Volt is proof of this. Where they don't work is in the OnStar division.I think this will continue to be a problem as there hasn't been much added to new phones lately (what else could anybody want?) so there will be many people who won't upgrade. My daughter held onto her iPhone 5 forever because the only thing we could see in the new phones were bigger screens (and better cameras). Software developers need to stop assuming the whole world upgrades as fast as they do. Plus, it can't be all that hard to support older clients with fewer features. On the server side, it's just a few "if" statements. Better yet, if the data was sent in XDML format the client can then display what it can and ignore what it cannot.
It all comes back to GM not having the best software developers in the world. Their infotainment and Onstar offerings are both proof of that.
I'm hanging onto my iPhone SE forever, I see no need to upgrade until the hardware fails and the battery stops working. I want my phone to be a phone, and fit in my pocket - I really don't understand why so many people out there are getting Phablets that don't fit into your pockets.