From what I've noticed, often it's not so much out right personal attacks that cause things like this to kick off, but rather the wording of a point, or a possible miss-interpretation of how something is worded.
Example:
Product A has significantly higher capabilities when rendering 3-D images then product B.
Reply:
If you took time to look into the technical details of product B, you would know that it out preforms product A, in most circumstances.
Now the person that reply was directed at can possibly misconstrue the first section of that post (underlined) as a jab at not doing his homework and not knowing the subject matter , which he may take offense to ,& there the snowball begins to roll downhill.
The person who posted that comment very likely meant no ill will it was just the choice of words and due to that as well as the variable of interpretation ,you end up with two people who are angry at each other. If you throw in things like people who are socially awkward or inept at communicating with others in real life, that effects how they communicate with others online as well....things like aspergers syndrome for example. Something you may account for if speaking to a person in real life with context, or mannerisms,are lost in text communication and the words are the only means to communicate a great deal (which in my opinion they arent capable of doing, since human interactions are very complex)
The majority of all of this that I've explained could easily be
avoided if people weren't so quickly offended, but I have to admit I've been pissed off by the way people word things in a condescending manner before too ....but I just tend to stop communicating with that person. Noones perfect
Just my 10¢