The carriers then responded, "I notice that there is no requirement that we allow any device that can make emergency calls. So we will only allow devices we also sell (and maybe a few other models, if they're popular enough that we can't get away with not allowing them). And if that means more people than necessary will have to buy new phones, we will happily sell them new phones."

The only reason that "iPads are just unserious computing devices for real work" is because Apple chooses to limit them.

I have a laptop which I only rarely use as a laptop - it moves between being connected to external monitor/keyboard/mouse in an office to being connected to external monitor/keyboard/mouse at home. I could get an iPad with a faster processor (my laptop is a few years old), that could connect to the same peripherals. The only reason it couldn't replace my laptop is because I can't run the same software on it.

Now, I understand why this is so. MacOS (or any other desktop OS) would not work at all well on a tablet interface, it would take a lot of work to make it work well, and those changes would make it less well suited to desktop use. Look at Windows 8, when Microsoft tried moving their desktop OS towards something that could also work on a tablet (or phone), and how unpopular those changes were. But that doesn't mean I have to like it (or wish iPads weren't so locked down, so I could run a different OS anyway even if Apple wouldn't support it).