The world went through a rear-engine phase with the VC-10 "Hushhh Power", the DC-9, and the B 727 "Nothin' hush here, buddy!"
Why are there no more rear engines, apart from the Bizjets which are too low to the ground to have them underslung? The good points at the time were that the engine noise was behind most of the pax, the wing was clean and more efficient, and asymmetrics were easier to handle.
But why no big rear-jets any more?