I wonder why Lee Jae-myung didn't appoint Kim Byung-joo as the first Defense Minister

No matter what, there is a certain culture in Korean society.
There is a sentiment regarding "surprises" (unexpected appointments), right?
There was the disparagement of Roh Moo-hyun for being a high school graduate... even Rhyu Si-min once mocked him by asking if he had an academic background complex. That kind of culture exists.
It makes no sense to say they didn't know about the desertion incident, and why appoint a former conscripted defense worker as Defense Minister? Instead of Kim Byung-joo?
The only way I can understand it is by thinking, "Was the personnel vetting for Kim Byung-joo so disastrous that they had to do this?"