Define "military value".In reality from a purely military perspective they were largely ineffective and the resources used on these missions could be better spent attacking targets that had more military value.
The sad truth about total war (where each nations pits all its ressources on the prosecution of said war), the civilian worker back in the factory becomes the foundation of every victory.
Without the worker, the military front will collapse in short order due to failing logistics.
Therefore, crippling the enemy warmaking capability is of prime importance.
The RAF in 1941 did not have the precision bombing ability nor the strenght to mount a bomber offensive against small targets like a factory complex without causing massive collateral damage.
Neither was it able to sustain the kind of losses incurred during daylight accompanying such an offensive.
Remember, the US Airforce had to break off it's long range attacks into germany in 1943 before the P51 was available as a long range escort.
Therefore, it concentrated on the one link in the chain it could reach, the housings of the factory workers. The main goal was not to kill the worker, but rather to destroy his home to break his morale.
Did it succeed? Yes and no. It didn't break the workers morale, although the Gestapo became icnreasingly worried about possible revolts after such assaults. At times, they even stopped parts of the holocauts (the famed Rosenstrasse Protests) for fear it might lit the spark of an rebellion.
But it did put an extreme strain on the german warmachine. Children had to be evacuated, workers were often absent after the bombings to look after their families and their belongings, and a massive buildup in air defenses was necessary.
After the war, it became clear that no revolt had happened, but during the war it was never clear if a revolt could not happen or what might have been a more usefull application of the bomber ressources.
IIRC (but I don't remember the book) what really broke the germans back was the attacks in 1944 on their fuel making infrastructure, and Speer remarked that a concetrated offensive on german powerplants would have been equally destructive on their production output.
The Blitz cleard the channel from british freigth shipping, hit several industrial targets like Coventry and brought the london east end, on which most of the attacks were concentrated, dangerously close to war weariness (before Buckingham Palace was hit), quite the opposite of the often portrayed picture of the plucky, unflappable englishman.The military futility of the bombing should have been even more clear to the Allies looking at the complete failure of the Blitz, yet they had gone even more enthusiastically through the same mistakes.
It probably would have been better for the germans to start mining all the seaports they could reach, but hindsight is always superior to the onthespot decision.
For the most time, the allies had a military goal in mind when attacking civilians, how again is that the same of letting prisoners of war starve on purpose, engaging in indiscriminate retaliation actions against the civilian population and shooting the inteligentsia of conquered nations?In reality even if the Allies hadn't reached the same monstrosity of the Nazi death camps at the same time their mindset wasn't so different when they were evaluating the value of harm done to the civilians.