The purpose of a forum is to exchange ideas, but people prefer to use them to feed their egos, hence they are either aggressively attacking someone else to appear stronger than they are, or they are defending themselves against these attacks. Someone who wishes to use a forum properly neither attacks others personally or bothers to defend themselves against personal attacks, this does not mean that one does not attack or defend ideas. Also most forum users confuse the two, if you attack their ideas they believe you are insulting them, if you defend your ideas they believe you are being egotistical.
Actually I disagree. When I participate in forums, besides the subject matter in question I'm also engaged in an exploration of the human condition in not what other posters say but in how they say it, taking into account their entire manner and personality. As personal attacks are an aspect of the human condition, I engage in that realm from time to time (on defense or on offense as well); I tend though to couple the personal with other content, to not only hit the poster's ego but deliver a message through the opening at the same time.
Furthermore, as you point out, personal attacks and attacks against ideas are often confused, so I don't necessarily let personal attacks slide if I'm worried the average poster may interpret it as a blow to my ideas.
Certainly pacifism is a valid option if that's your way, but I wouldn't unequivocally equate it with "using a forum properly".
As far as being egotistical about it, I believe you can engage
in personal defense or attack without actually taking it
personally. For example, if all personal attacks bounce off Crow like water, I would hypothesize that this mechanism is different and separate from that pertaining to his moral or philosophical decision to refrain from or engage in personal defense / attack; I know it is separate in my case.
The simple souls that populate forums, for the most part, have experience of only two modes of being.
Aggressive, and defensive.
Everything else is merely a variation on those two themes.
You're either the one, or the other, or both, at different times.
What do you think? Is it conceivable that other modes of being exist?
Could you describe them if you had never encountered them before?
Could you understand what was going on?
If you could, by what mechanism would you be able to understand?
Logic dictates that any given forum post could be more
aggressive or defensive to varying extents, both
aggressive and defensive to respectively varying extents, or neither
aggressive nor defensive at all. These are the only three options, that is, if you insist on using such labels. This framework could be applied to any post, but is hardly definitive of course as countless other frameworks could be applied to the same post simultaneously, such as how humorous it is, how brave it is, etc; a post could be both defensive and funny, for example. To look at everything exclusively in terms of aggressiveness or defensiveness is not only an extreme polarization of the spectrum of aggressiveness / defensiveness, it's also ignoring all other possible types of spectrums and I should think is most bizarre.