Did the Allies in WWII switch from precision bombing to area bombing primarily to justify otherwise inadequate technology? If not, why did the shift happen?

I've finished rereading Rhodes' The Making of the Atomic Bomb this past week, for context. Looking back on it, Rhodes makes abundantly clear that understanding the use of the atomic bomb requires understanding the shift from precision bombing of military targets to area bombing of cities of civilians, which seems to have been more or less complete before the atomic bombs were used. He identifies, as the central figures in bringing this shift about, Arthur Harris and Curtis LeMay, the former as a way to justify night bombing in Germany and the latter as a way to justify the B-29 in Japan. I want to check to see if this is accurate, because it's clearly important to understand how the Allies go from Roosevelt condemning the bombing of civilians in 1939 to, six years later, the Target Committee recommending cities as targets for the atomic bomb without any qualms.