Cedarjet has pretty much summed it up.
The following needs to be added to complete the picture:
1. In 1946 the US had an industry geared up for war, a population of around 200,000,000, massive natural resources, no food shortages, no physical damage to its industrial infrastructure and the advantage from an agreement with the UK that, during WW2, the US would build transports whilst all the UK production would be on warplanes (the only exception was the Avro York).
On the other hand the UK had a population of around 42,000,000, few natural resources, a food shortage, massive damage to both the industrial and domestic infrastructure and no history of new airliner building for 8 years.
2. Yet in a very short period of 10 years the following types helped rebuild British and many world airlines and air forces (the military and civil developments in both the US and UK are totally interlinked in the first 30 years after 1946), in some cases led the technology, broke world records and, whilst some types led the industry down blind alleys, at least showed the way to go.
Avro: Tudor, Vulcan
Bristol: Brabazon, Britannia
de Havilland: Vampire, Venom, Dove, Heron, Comet.
English Electric: P1/Lightning
Fairey: FD1, FD2
Rolls Royce (engines) Dart, Derwent, Avon, Tay
Vickers: Viking, Viscount, Valiant
After 1956 we move on to the era of the jet transport and, as already mentioned in the thread, the heavy hand of BOAC and BEA who so tightly drew the design outlines of both the VC10 and Trident that they made sure that neither would be anything but superbly over engineered, totally reliable, white elephants, as far as the rest of the world was concerned.
Fortunately the dead hand of bureaucracy did not fall on the 1-11 or the 146 and both have sold relatively well as did the 748. On the military side, only in the last 5 years have any designs come near to the superb Harrier and there is still nothing in service to equal its flexibility.
To go back to the original point, had the Comet sold, say around 900 as the 707 eventually did, the question has to be asked as to the capacity of de Havilland to cope.
Resources at both Hatfield and Chester would have been stretched to breaking point to produce the Dove, Heron, Vampire, Venom, Sea Vixen and the 400+ Comets that may have been required between 1953 and 1957