Airship Recruiting
I'd suggest that defence companies are interested in more than an Air Rank's reputation - influence and insider knowledge are probably higher up the list of 'what can Air Marshal Bloggs do for us?'.
Are Air Ranks clueless - no of course not; have they worked hard to get where they are - yes absolutely; do defence companies hope to influence defence spending by employing recently departed star ranked officers - I believe so (after all, they are not charitable organisations).
Has the employment of star rank officers led to some dodgy procurement decisions - I don't know, but it is easy to take a cynical view especially as defence companies don't especially enjoy a whiter than white reputation.