That's the worry of a smart, friendly foreign observer, who tells me that:
Some, if not many, of those still serving see well-paid second employment as a consultant or DoD contractor as part of their retirement package, a perk if you like. They do not wish to rock the boat in case it sinks and they can't climb in when they retire. There will be individual exceptions that disprove the rule, but this arrangement is, in the round, not good value for your tax-payers' dollars.
Thomas E. Ricks covered the U.S. military for the Washington Post from 2000 through 2008.