Why can't we grow beards?

essentially, try growing a fucking beard and strapping up your headgear. strap up that gas mask and see what happens. everyone doesn't grow facial hair the same lengths, etc and when dudes go grey, are they supposed to die it? That's why... nothing more nothing less

Beards are not a hindrance and should be allowed

I close trimmed beard and/or mustache should be allowed on men.
Back in the 1950's and early 60's, I remember white males were not allowed a mustache but blacks could have one. I never though that was fair. If a female has a "mustache" she can have electronics or laser it and it will not come back. Simple...! All the troops in Iraq and Afghanistan have beards. When they return stateside they have to shave them off...! The military is still fxxxed-up in many ways. Really too bad...!

I believe it probably has something to do with personal hygiene, the same reason for very short hair. Easier to maintain in a field environment and less chance of getting any unwanted critters.

Gas masks don't seal with a beard in the way

I answered this quite a while ago but I think my answer bears repeating: gas masks.
Soldiers were allowed beards up to our involvement in WWI -- when it was discovered that a beards and long moustaches prevented a proper seal with a gas mask. I don't rememember exactly how it played out but it made its way into uniform regulations at that time and it has been there ever since. A well trimmed moustache is acceptable but it has to comply with strict guidelines so that it does not interfere with the proper functioning of the mask. Beards, on the other hand, cannot be trimmed so that they don't impede a seal. They are, therefore, verboten.
Exceptions to this regulation exist for soldiers in covert status, i.e. special ops, counter intel, CID, etc. Other than that -- you need to be clean shaven if on duty.

Basically it comes down appearance and discipline. Back in the day it was a dog and pony show. Appearances were everything.

LOL @ Psychotic people. Your aware that "psychotic people" slip past the MEPS and inprocessing screening and it is very difficult at times to weed them out. So I would not say that suddenly they are "allowed" in the military......they have always been cases where they slip past. When I was in the beard prevented a seal with the NBC mask and that is why they were forbidden back then. I have no idea why they are banned now.

If you want to grow a beard, join a special unit. I met an Army DEA unit on TDY once and the whole unit had beards and long hair but, that was because of "where" they were stationed and they had to be able to blend in with the local population to do their job effectively.

One big reason (the only legit reason) is that they can be grabbed and held when in hand to hand combat. That's why cops don't usually have them.