The wikipedia article makes it look like the design was inherently flawed. Entirely possible that venture capital was (at least subjectively) allocated badly AND this project shouldn't have received more funding anyway.
An SSTO is an ambitious design in general. That, plus a new engine design, was (in retrospect) too much for a startup company to take on. Just the powered landing system would have been ambitious enough.
If there's ever some kind of standard that emerges for rockets maybe a company like this can make an interim payload stage to add to recover the vehicle. Like how satellites are gaining more and more standard parts and form factors.
As presently any system like that I assume is pretty must bespoke per rocket family.