I'm not condoning the firebombing of Germany but it was a military necessity and the logical thing to do. The Germans themselves used mass terror bombings against Britain, Russia, Poland and Holland. The threat of flak guns forced bombers to rise to very high altitudes and at high altitude, precision bombing was impossible. High altitude precision bombing only became feasible in the 80s with the guided munitions revolution.

Back then, the only way to destroy enemy industry was area firebombing by mass formations of hundreds of aircraft. Thousands of bombs were dropped and together they did catastrophic damage regardless of whether they hit factories or not. The mass bombings helped to dehouse enemy population and cripple industrial production.

The allies had no better option. They tried precision bombing with high explosives against both Japan and Germany but failed. They swiftly attained victory once they switched to area firebombing. The German bombing campaign against Britain failed because they did not realize the merits of area bombing.

Arthur Harris later noted that if the Germans had adopted mass area firebombing tactics against Britain in 1940, the British war effort would've been severely crippled.