I personally think the time will come again for aircraft like that, but that the conditions for them to have commercial success are actually, ironically, the presence of viable long range supersonic transport (Boom or whatever makes it there first).
My pet theory is that at that point the business model for longhaul bifurcates and you end up with a two tier system. Low cost, high capacity, relatively lower speed hub and spoke model (suiting large 4 engined a/c) and high cost, high speed, low capacity point to point.
but that's simply one theory...