I assume that most junior officers own a car so the point that "you need a car" at Marham, while true, is presumably aimed at JRs. So I would be genuinely interested to see a list of locations to which a JR could reasonably expect to be assigned at which the lack of a car would not be considered a problem. A few lucky ones at Northolt and MOD aren't really representative of the majority. Waddington, Brize, Odiham and Benson I should imagine are OK but how much do you spend on taxis before buying an old car becomes better value?
When I spent time at Marham I lived about 35 minutes' drive away near Ely. That is actually IN civilisation, an hour to London by rail and jobs galore for the spouse in Cambridge only 10 miles away. Some might wince at a 35 minute commute; anyone working in a city would bite your arm off for it, especially when half the cost is covered by HDT.