Hitler had specifically prohibited the Luftwaffe from bombing civilians and creating terror among civilians. Goering had also specified that "every effort should be made to avoid unnecessary loss of life amongst the civilian population." and that bombing of non-military or industrial targets was forbidden. The first bombing of London on 23 Aug. was an accident. The bombers were off course and did not know they had bombed London. They also dropped high explosives and very few incendiary devices. When Britain retaliated and bombed Berlin on 25 Aug. Hitler kept to his original plan of not targeting cities to create mass panic and was shocked the British had done so. It wasn't until 5 Sept that Hitler rescinded his prohibition on bombing civilian targets in retaliation for continued British bombing of civilians in Berlin. Britain used magnesium incendiary bombs in Berlin's suburbs on the 25 Aug attack. Germany used incendiary bombs on 14 Nov. in its attack on Coventry where it attacked both industrial and civilian targets. The heavy incendiary attack on London wasn't until 29 Dec. High explosives were primarily used on London before that. One can just as easily make the case that the British "invented" incendiary bombing as a means to terrorize civilians.
There is quite a healthy debate among historians as to why the bombing was stopped so I have no idea why you imagine historians are "so unwilling to find out why, or even to ask"
John Thornton