It's fun and easy to say "Just play your game and leave well enough alone," because your game isn't the one constantly being attacked. But that's not what 4e haters are doing, and they are 4e haters, not 3e fans, because "liking 3e" is not enough for them, they have to put down 4e. Hey, maybe people who like 4e will play their game happily and leave well enough alone when the other side stops poking them so much.
An opinion is not an attack. Let me demonstrate.
"Katy Perry's so-called music is rubbish."
Observe that Katy Perry is unharmed. Now, obviously Ms. Perry isn't here to be offended. If she were, I might say,
"I can't say I'm much of a fan of your music, Ms. Perry, but it was nice to meet you."
But even if she overheard the first, perhaps as I was unaware she was present, she might be offended, but could not claim to be attacked. Observe, however, if I said,
"Your music sucks. I wish you had never been born."
That's different. That's a verbal attack.
Now imagine we were in a moderated environment. Perhaps every time someone referred to her music as rubbish, a fight broke out. A moderator might step in and say, "Look, no calling that music rubbish. We're all here just to have a good time." That becomes a stickier issue. I believe, personally, that some things can be called rubbish. At the same time, it's not always kind or worthwhile to do so. I don't go around telling kids that Pokemon cartoons are rubbish, even though they pretty much are. It's a matter of tact and compassion. I think there is an argument to be made that adults can, and perhaps should, be frank about discussing things of pertinence (like, for instance, RPGs, on an RPG site). On the other hand, there is a lot to be said for civility, even enforced civility. As we know in what direction policy has been laid out on EN World, discussion of what constitutes an edition war is probably not all the fruitful.
First, edition wars are not allowed. If you see something that looks like an edition war, either you're wrong, or the mods haven't gotten the report yet. If you're wrong, there's a good chance you are about to start an edition war when you draw your saber, becoming the very thing you swore to destroy.
Second, most of the things that lead to edition wars are already not allowed. Ad hominem attacks, blanket negative evaluative statements about games, and claiming to speak for the other side of an argument are already against the rules. Fallacious arguments are strongly frowned upon. Something is unlikely to even venture into edition war territory during normal business hours. By the time someone gets suspended or whatever, people are usually crossing the warning tape that says "Do Not Go Into the Do Not Go Place."
People saying things about games that you do not like about games you do like is not an edition war. If they are saying inaccurate things, you are entitled to correct them. If they say things with which you disagree, you are welcome to disagree. But it's not a war until someone sets aside civility and attacks. Until then, it's just a difference of opinion.