Delta Force is the top of the top of Special Operations Groups. These are not people who just joined four years ago, their job is exactly not to look like a soldier, to look more at place where they are operating in.
Hell, in Special Forces? you can wear your uniform in any fashion. Pants un-tucked, bootlaces out, hell, sometimes you dont even have to wear the uniform at all, the least of which is facial hair grooming.
Commanders learned early on in Afghanistan that their culture views beards very highly, many village elders and sheiks didn't take Operators seriously for the sole reason of not having beards.
There are actually four worlds in the Army, at least, National Guard, whom everyone else hates with a passion, TRADOC, people responsible for training units and teaching the regulations and standards, Regular Army, exactly what it says on the tin, and Special Operations, which is an entirely different world from everything else.
Also, dont think just anyone can join Delta Force, they often choose candidates from Special Forces units, and even then it's usually the top 10%. Special Forces even have a rigorous trial, Soldier's who pass Selection often are on their second, third, or fourth try through, and even selection is tough that a majority of drop-outs are due to medical reasons during the process. Once passed that, then you spend about a year and a half taking various classes like Jump School, Sapper, Combat Diving, Survive Escape Resist Evade, often times Ranger Course, and a slew of other schools that are mandatory.
So the people in Delta? they kind of earned the right to wear a beard, they are kind of badasses to begin with.
