While Node-RED is indeed integrated into HA - and a lot of Node-RED users (especially on the forum) use Node-RED for home automation - it is not the only market segment for dashboard - so we won't be adopting HA dashboard. Of course if someone wanted to do a much better HA /Node-RED integration we wouldn't stand in the way - it's just not something we are considering.
Like-wise the unified-red project - kudos to them - looks like they have taken it forwards - certainly with the multi-user aspects - but from the feedback above that does seem to have made it somewhat more complex to get going, which is not what we want either...
My current 2c is that the current sweet spot is about right - ie ease of get going, does the basics, beginners and non-programmers can use it. 1 node to 1 widget is easy to grasp, wire, make sense of in a flow. More advanced things can be (and are) create-able by more skilled users using ui-builder or fully custom solutions. Certainly if they wish to create their own product, and the basic dashboard should not try to do everything. (though a better chart would help 
As usual I like parts from several of the existing alternatives/proposals/idea - eg Julian has/is doing some great work on security that really does need to be built in from the start, web-components look really interesting (but are/will they take off/be supported enough), and @tve 's ideas re better layout are appealing.
