On a serious-ish note:
Many people find it difficult to enter into an argument because they learned at an early age that when they were around an argument (parental), it was a hostile situation. This was a form of confrontation that they would prefer to not take part in, and thus avoid it even as an adult.
No matter what level the argument takes, it should be done with respect and be allowed to be a two way discussion. Sadly, many people argue for the sake of trying to win and not for the sake of an intellectual conversation.