Arguements and discussions

Today while following a discussion on a certain web list regarding the differences between css driven layouts and table based layouts, i made the “mistake” of posting and stating that even table based layouts can be css driven, adding that tables are html elements as well, thus containers that support styiling like any other element. The subject was not the point…what intrigued me was the reaction of a certain designer that almost called me names for the statement I made.
Now usually when I see something like that, in the first moments I think “hey, maybe the guy is far more experienced than me” and I go back to studying things. And perhaps he is more experienced, I wouldn’t know.
But no matter how much I study, I can’t understand that way of arguing. After all, such a discussion is supposed to be instructional, exchanging oppinions, asking questions, getting answers, all in a firendly manner (more or less). So it got me thinking, what makes a person think that his own ideas are universal truths or axioms , based on which one can treat people as they like?
Not really that it would matter …yet I’m used to another type of discussions and I usually like to think that designers are more educated and sensitive.

Any thoughts?