Differing experiences, I suppose. Most everyone I know has a connection to the US Military. As a conservative estimate, I'd guess that I interact with a couple thousand current and former service members every month. They are, on average, smarter, better educated, and better behaved than their non-service peers*.
The US Military is a large organization, and while it attracts a broad cross-section of America, it also appeals to a few unsavory segments. Gangbangers come for the training. CallofDutyWarriors come because they confuse real life with video games. The military gets a fair share of maladjusted individuals that will, contrary to considerable training, conduct themselves inappropriately when given the chance.
This activity (it is real) is embarrasing. It is inexcusable. I hope the guilty parties are punished appropriately. That it occured is not an indictment of service in general, or of the hundreds of thousands of servicemembers that don't do such things.
* low standard, I admit. In most cases, a young Soldiers "peer" is a frat boy college kid away from home for the first time, or an 18 year old townie working for a subsistance wage and out on the town the one night a month he can afford it.