Generals and Admirals in the know have very current knowledge about capability gaps, and how to better serve the customer. Given that they already have a 1 year cooling off period for any contract they directly oversaw (most weapons programs are overseen by O6 & O5s, or junior SES).

We're in this very sensitive time where you want senior Warfighters and planners are vitally needed for a massive modernization campaign as we shift US Defense away from counter-terrorism and towards peer nation-states. US Defense was lulled during Iraq and Afghanistan, thinking counter-insurgency is what we'll be fighting forever.

The military way of thinking and planning battle campaigns, and knowledge of Order of Battle, both our own, but also of our enemies - that is perishable knowledge in these senior officer's heads.

Additionally I would like to bring up one other thing - although troops matter a great deal, and so does training, much of combat comes down to weapons systems.

Weapon Systems - Better, faster, cheaper, more accurate, more lethal, more mass-producable, less resource intensive, more logistically mobile - is what wins wars.