RousseauX
Donor
They were able to do so because the British specifically refuse to be baited into unwise engagement by those bombardments.If the Germans had won the war in France quickly, say with a smashing victory at the Marne in 1914, then the idea of an invasion of Britain becomes a possibility. How plausible a possibility is open to debate, but it is certainly a more plausible scenario than Sealion, as the High Seas Fleet is a much more formidable force vis-a-vis the Royal Navy than Hitler's navy was in 1940.
IOTL, the High Seas Fleet was able to bombard British coastal communities on the east coast on more than one occasion.