Coldsteel,
Youtube videos do make the beard policy look ridiculous. In fact, Youtube videos can make anything and everything under the sun look ridiculous.
Technically, there is no such thing as beard policy. There is no written policy or rule with the JW’s that you will be disfellowshipped for wearing the beard. Yes, you are discouraged to wear one, you may lose your privileges, etc, but won’t be disfellowshipped.
Why do religions have such policies? To understand this, first you need to remember that all religions in this world are technically like corporate organizations with written and unwritten rules of conduct. You will have such policies in all religions. Some disallow beards, some force circumcision, some want special garments to be worn, some encourage flagellation, etc. Each religion follows rules from their holy books and frames new ones which they feel needs to be adhered to either gain new followers or to create an environment of decency for existing followers.
In south India, there is a temple which doesn’t allow menstruating females to come in, and there is a religious festival where men are asked to wear full black clothes and not go near women during this 41 day period.
Does religion have a monopoly over making policies? No. In many corporate organizations, there is a formal dress policy where employees who are into client facing jobs are not allowed to wear casuals during client interactions. In my organization, casual clothing is not allowed during the weekdays. People may like wearing long hair or pony tails, but many multinational companies disallow that. Even though they may not kick you out, but they won’t allow such people to represent the company in client meetings. So if you work in an organization, you either follow those rules or you get out. There are countries who allow beards in the military while some who don’t. Policies are everywhere.
You have rules on this forum too, which have been excellently set up to avoid un-civil people to ruin discussions. People may feel that they have a right to be annoying. People may feel that discussing pornography and sexual activities are not taboo. But you are not allowed to do that on this forum, and we are thankful for that. If you don’t agree, don’t join or be ready to be banned.
What about stumbling? A person can pretty much stumble over any point of personal preference. Jesus did wear a beard, but also wore seamless fringed robes and jewish sandals. Russell too kept a beard, but without a mustache and wore glasses much lower on his nose bridge and also chose to have a celibate marriage. These were personal preferences. There nothing that indicates that Russell was imitating Jesus in keeping his beard, because if he was, he would have also kept a mustache. Hence there is no point in wearing a beard by using an argument that Jesus and Russell had one.
Like corporate organizations, religious organizations have complete authority to make rules and change them. Since belonging to a religion is a voluntary choice, a person either lives with those rules or he gets out of it. Post which, he either moves on in life or keeps cribbing about his ex-religion’s policies.