...I don't get why this argument doesn't end with the simple solution of allowing iPads onto corporate WiFi networks.

Well, it turns out , either:

Here's a scenario that could give network managers pause: iPad owners looking to avoid downloading high-definition videos or movies over LTE to avoid steep data costs may instead do so over Wi-Fi at work.

"In a 100-person office, if just 20 percent are using the new iPad, you are talking about a tremendous amount of network traffic," [Ed O'Connell, senior product manager for WAN optimization products at Blue Coat Systems] said...

Hang on a second. You have a 100-person office and 20 percent of them are watching March Madness in HD on their iPads? You've got bigger problems than network traffic, Mr. IT Manager Dude.