A lot of effort is in fact being placed in these areas. NASA has had the N+1, N+2, etc., programs. There is a lot of interest in distributed electric propulsi

A lot of effort is in fact being placed in these areas. NASA has had the N+1, N+2, etc., programs. There is a lot of interest in distributed electric propulsion (see the ESAero work), and Europe is working on their Clean Sky programs which are actively trying to push what is now called "Open Rotor" propulsion technologies. What is missing is major civil airframer (i.e., Boeing, Airbus) commitment to take some risks with new concepts that go beyond traditional tube-and-wing. Unfortunately, the outsourcing disasters that happened with 787 have convinced Boeing management that they "took too much risk" with the 787, conflating programmatic and technical risk, and it's hard to be sanguine about Boeing prospects for going beyond traditional configurations.