The DVR is basically a simple PC wityh a hard disk in it.
It already knows how to stream its recorded content when connected to the TV.
it already knows how to communicate on the network to get content and send info out.
If I am on my home network, I would expect to be able to locally stream DVR recorded content to a laptop or tablet connected to the same network.
What is the reason this capability does not exist since it is available on ther services?
You're correct. You can currently only watch programming recorded on a DVR directly from the DVR on a TV that is directly connected. Streaming DVR content is not supported. I will pass along your suggestion to our video team for future consideration.
Sounds to me like you need to go the TiVo route. I can do all of this right now using a Bolt with a Mini in the bedroom or via the TiVo app on my phone while anywhere on my home network.