Soddim,
I'm not convinced that Typhoon's requirement, though written in the Cold War, isn't (fortuitously) exactly what is required today.
A multi-role, AD heavy, network-enabled platform, capable of rapid deployment and OOA ops.
Capable of beating a 'developed Flanker' threat.
Capable of delivering stand-off PGMs.
With low through life costs and low operating costs.
This requirement, though written more than 20 years ago has arguably stood the test of time!
I'd agree that quantity has a quality all of its own, but that's not accepted by HMG, who aspire only to be able to simultaneously deploy 84 FJs at readiness. Better, in that case, for them to be EF Typhoons than F-16s, I'd say. Moreover the quantity argument only holds water if the large number of airframes are sufficiently capable (and the F-16 lacks a robust modern BVR capability, isn't net-enabled, and and and....) and have low costs of ownership and low through life support costs. F-16s wouldn't meet those criteria, though Gripens might.
Normally I'd agree with you about the armed forces 'picking up the bill' and paying the consequences for late, over-budget kit, and even in this instance, I think it unfortunate that some of Typhoon's costs aren't being met by the DTI! But this time, late is actually an advantage, and the damned thing is still cheaper (unit cost) than F-15 or even Super Hornet.
Yes there have been cock-ups galore, but the end result is that the RAF's getting a great aircraft at a good price when it needs it (not when it thought it would need it, but as you've pointed out, the threat didn't develop as or when we expected....)