Because there are 2 meanings of Sealion :Hey ljadw,
re "As I expected : you forgot the principal reason : THE WEATHER."
Why do you think the weather was the principal reason?
The reason I ask is that I do not see how the weather, be it clear and sunny or dark and stormy, would matter if the Germans do not have air superiority, and control (naval) of the English Channel. If they did not control both there is no way they would survive (intact) the crossing.
the traditional , in reality wrong meaning : an invasion of Britain
and the real one , the only one which was possible = the occupation of Britain .
After 15 September an invasion of Britain was impossible because of the weather .The barges transporting men and supplies would not survive the Autumn storms .
It is even probable that an invasion would not be possible in August, as an invasion would require a long buildup .It would take months to occupy Britain by fighting and months of transports that had to cross the Channel .
A fighting Sealion was impossible without air supremacy and impossible with air supremacy .The same for naval supremacy .
Goering hoped that an early victory in the Battle of Britain would force the UK government to negotiate ( which means : capitulate )WITHOUT ANY NEED FOR AN INVASION . (my emphasis ) . Source :Stephen Bungay . But the hope of Goering was self-deceit.
No one proposed to execute Overlord in the Autumn,thus why would Sealion (with a weak Germany ) be possible in the Autumn ?
General time was Germany's biggest enemy ,and Germany could do nothing against general time .
The only way an occupation of Britain could be possible was if,when, after Britain was giving up .
A successful invasion of Britain in 1940 had the same chance of success as a successful invasion of Japan in 1942 .
Britain did not capitulate during the Blitz ,when every night countless civilians were killed/wounded , thus what Goering hoped was an illusion .
Occupation after invasion was impossible .
Occupation without invasion : idem ,with the exception of the US declaring publicly that they would not help Britain. But since August 1940 (GOP convention ) this was excluded .