The industry dismissed liquid reactors because of the problem extracting weapon grade material. Uranium based reactors where not as safe nor as cheap. During the cold war this made sense but not today.
It has also been about people protection their jobs. The uranium based industry can't say that something else is better because then they might lose their jobs. And who do you think the politicians ask when they want advice?
Or perhaps you've been swept up by the breathless prose of popular science articles?
As far from peak uranium as we appear to be, there is simply no need to explore alternative fuel sources. Fuel is not scarce. The capital (political and financial) to build infrastructure - both power plants and reprocessing plants - is.
In that climate, the (never-been-built-or-licensed) LFTR is only a game-changer if its construction (and licensing and R&D) costs are an order of magnitude lower than those of current-gen reactors. This I highly doubt.
The reactors he presented appeared to be much simpler (so... they'd likely be cheaper).