Those people would appear to have some consistency in their logic. On the other hand, those that believe the use of WMD's on Japanese cities and the wholesale destruction of Dresden were justified and "well-deserved" are the same people who are shocked and mystified when the US is attacked in such an indiscriminate manner. They would believe that nothing could possibly justify that kind of slaughter of innocents. An inconsistent logic.
As I pointed out above, nothing about the reduction of Dresden, Hiroshima or Nagasaki was indiscriminate - they were military targets in a war which had been declared by the governments of Japan and Germany on the United States, and the the United States' actions were measured and restrained responses to Germany's V-2 rocket attacks on purely civilian targets in the territory of a US ally and the unprovoked attack on the US Navy at Pearl Harbor as well as the atrocities committed against the civilian population of the Philippines.
To compare Al-Qaeda's unprovoked attack on a purely civilian target located in a nation that was not currently enagged in hostilities with the homelands or even the countries of residence of the bombers to the US' prosecution of war in Wordl War II is an embarrassing exercise in special pleading and moral equivalence.