There is a big difference with an iPhone ($750 MSRP on the iPhone 5) and a car (~27K if you want the features which I am advocating the updates for).
While there are people that do keep phones for 5-10 years, a LOT of people seem to replace them every couple of years. I am on a 2-3 year cycle myself with my phone. For cars the cycles do vary based on person, but my history this been as been an average of 5 years.
So where am I going with this? Your points are valid; however, in this day in age the idea that you can buy the hardware and get updates for a period of time is a really big selling point. I don't know what car companies are doing software upgrades for their infotainment systems, but I think it would say great things about Mazda if they decided to do it. While the handling the vehicle, fuel consumption, styling and of course quality are more important factors than on-board tech, the on-board tech is a selling point and it would make sense, IMHO, to throw in upgrades to that system for the first 3 years/36,000 miles.