[varjag]

Well, Concorde wasn't allowed supersonic over the populated areas of the USA, to be exact. Was never a problem elsewhere, and some of the contemporary subsonic airliners were actually louder than the Concorde.

As you say, catastrophes didn't help either, although they occur regularly with vanilla airplanes as well. Fuel efficiency is indeed a problem; however there was no further R&D put into the programme since the 1970s, so no wonder. A modern 747 is certainly way more fuel efficient than the original mid-1960s project.