In the beginning there was Usenet. It was a wonderful microcosmos of technical expertise and niche hobbies. Then 1993 came and the constant flood of new users overwhelmed the culture and ability to enforce norms [1]. Truthfully, it didn't begin with Usenet. It's the old dilemma of universal access and freedom versus mutual coercion, mutually agreed upon. Even before that, Aristotle wrote "That which is common to the greatest number gets the least amount of care. Men pay most attention to what is their own: they care less for what is common." Those who don't know history are destined to repeat it.
[1] https://en.wikipedia.org/wiki/Eternal_September