That's what you get when you ignore ethics
Essentially DEF CON seems to sell out to the highest bidder. In European conferences not even sponsors are well visible. A recruiting event for the military would be absolutely unimaginable, and even if it happened, most people would try their best to sabotage it.
In fact a few years ago during the CCC congress, some artists hired actors to act as recruiters for such organizations. Most people downright rejected those, while some people turned up to the arranged meeting with hidden microphones and cameras. Nobody took the offer.