Should beards be allowed in the Marine Corps?

So, there is this connotation that beards are unprofessional. This may have been true at one point, but no one can really argue that this is true today: statistically, bearded men get paid more and are preferred for management. Now here is the issue: beards used to be common in the military, but now is the exception to the rule (as a religious factor- and that is only in the Army!) In other works, if you are Sikh and enlist in the USMC, good-bye facial hair- you are just like anyone else...

The entire purpose of the clean shave was to ensure you could get a good seal on your gas mask, which is why you look at history and see those glorious beards and mustaches. In the early 1900s, it was stated that this facial hair will kill you, because you cannot get a good seal on your gas mask... While recently (allegedly) it was proven (by the Army) to be a non-factor in getting a good seal- I cannot confirm nor deny that this happened- but it does beg the question: if facial hair is a non-issue as it pertains to warfare, then why is it an issue?

Although I approve of the current policy, I wonder- if an Army Sikh officer can get a good seal on a gas mask with a full beard, then why can't the rest of us? I mean, it's not exactly tradition to have a clean shave; just look at a list of the Commandants! So... is it really unprofessional to have a beard, or is it a matter of being hard to regulate? And if it is it a matter of regulation, is it simply a lack of empathy on the subject? Keep in mind I don't care either way; I will maintain a clean shave because I look weird if I don't, but when you cut out tradition, and history, and practicality... It just doesn't make sense. Your thoughts, ladies and gents...