Building diy multitouch tables has been possible for a long time now, given time, space and budget for that project.
I fully agree that it ultimately boils down to software: Can I implement my favorite board game for my multitouch interface? Yes. Can I bring that game to the table faster by just buying a physical copy? Yes.
I happen to have two 42" touch displays set aside for such a project - a unused backup unit destined for the living room for 200€, and damaged unit for dev work (for free). Since I bought them about 2 years ago, I also bought at least double that value of physical board games in retail, plus a Kickstarter board game. Go figure why.
However, I did play the digital version of Root on one of them, and enjoyed it very much. I should get Dune, too.
NB: I regularly see multitouch tables at trade shows. Nice eye catcher and useful to present some products or the multitude of services big companies offer.