Here are three early pictures from 44-46 - one shows the second E_W runway under construction. You can see that there is almost nothing in the way to the west whereas to the east there are roads, villages and factories.
he old sewage works (front in second picture) - now the location of T5 (I say nothing) - was a major driver as the Council wanted a very significant amount of cash to move it elsewhere - which wasn't forthcoming until the 1980's