It used to be that way, and probably will be that way again. I know of a few of people who got an early testicular cancer diagnosis that way. So it seems that there is a medical use for it.

Military medical exam is not for medical diagnosis! They don't care, they're there to enforce. It's worth the same as a dude pissing into urinal next to you and saying "nice balls mate". For official medical diagnosis you have to go through the procedures within healthcare system in your country.