The marketplace of ideas...
It used to be through publications. Publications takes commitment and time. Not just everybody can do it. It was a natural selection at work.
The internet era and the anonymity that the internet provides breeds trolls and intellectual midgets.
In the past people have to go face to face to debate.
Nowadays people like sybill, etc. will flame other from the safety of their computer and never be held accountable for their disruptions and childish behavior.
The internet... such a powerful tool... but also so destructive.