Doesn't DIAL simply cover "Discovery And Launch"?

As I understand it, even the Netflix TV client has custom extensions to perform more than the most basic functionality.

You also need to get that app approved onto the TV, which, chances are, require an update. Sadly that means that you're likely never getting support for the majority of the devices already in the field.

DIAL's time has come and gone. Adoption during the SmartTV hey day 5+ years ago may have made it a contender.