MHL link from iPhone: Questions

My TV has MHL. The link is designed to provide mirroring from mobile devices, though the spec was written for Apple competitors. I have questions:

1. Coming from my iPhone 5S I can purchase a cable, at 3x to 4x the cost of one for a competitor, why is that? Is there firmware in the Apple-based cable?

2. Why do the cable instructions say I must run "Personal Hotspot" to make the link work? I am not using it as a router!

3. why do apps not work? If you are mirroring why is it not just a screen grab? I have apps with libraries of videos I want to watch but have to access them via a web browser instead of the app?

4. What is Apple's stance on the MHL standard?