There's some logic there.

The trouble is that the actual living part of a big tree like that is a very thin ring just under the bark. It's not like grafting a twig onto another twig where most of the wood is still alive and growing. And there's also no way to get all the tiny water capillaries to line up.

Much like with with other issues they try to take a solution which works in one simple area and try to just copy it over to a much bigger more complex problem then wonder why it fails. I mean why not replace all prisons and police with more therapy, it worked for a couple of shoplifters once.