I am not talking about official, clinical OCD (Obsessive Compulsive Disorder). I am using the term loosely and casually.
I see this type of obsessive behavior in religious circles (but I am certain it exists in purely secular fora) where it seems that not a few blogs and those commenting on blogs have a compulsive need to correct and to criticize someone somewhere. Although I am not a psychologist, my common sense tells me that the excessive need to correct others and to posture as superior in knowledge signals a certain fragility, a sense of fear, inadequacy, and insecurity. Of course, it's a matter of degree.
If you are excited about what you know, then indeed share it. Invite others to learn more along with you. There is no need to ridicule or to be sarcastic. Ridicule and sarcasm give us clues that the agenda is more than just educating others. And just showing off really teaches no one anything and merely begs to be ignored.
This neurotic type of "knowledge-posturing" is often seen on the internet: X is a fool because X is so stupid. I will show X up! (This underlying message is usually disguised in some condescending way that facilitates deniability, but the real agenda remains.)
In the end, this type of posturing is fruitless and unproductive. It makes the person posturing feel good about himself, but even that feeling won't last long and requires another round of finding some new others to target. Hypercriticism is a waste of time for all involved: the perpetrator, the target, and the target foolish enough to respond in kind.
I recall seeing this excessive behavior, as many of you have, in the classroom where sometimes a student decides to become the class critic or class show-off. You also see it at times among some grad students. What usually happens? Everyone tunes out the class critic and show-off once they realize this guy is some sort of neurotic. And so many of the non-neurotic will tune out blogs and blog participants who do the same sort of thing so precious time can be saved for something useful.
(Image in public domain)