Doxing is important because some people are working on their Zodiac Killer investigatory thesis about the origin of the lolcow species... or so I have been told.
Personally I see it as a point of non-interference. Spergs react in a big way when you dox them, even normies.
I'd be willing to bet dollars to donuts that if you suddenly required every person on this site to freely dox themselves to keep posting... the farms would be a ghost server. Outside of a few random people, who likely have already been doxed, the number of willing self-doxers is going to be low.
The point isn't even if doxing will result in harassment or griefing, it might not, the point is that most people, normies and spergs alike, firmly believe that it will.
The anticipation of pain can be just as effective as pain itself.
That is, the act of doxing doesn't even require a negative end result, simply doing it will have a profound effect upon the sperg regardless, which in turn inherently taints their future actions, potentially even causing them to shut down and retreat offline. Not necessarily by choice either. When you start doxing the sperg's parents and loved ones you are likely going to bring about a shit show of an "intervention" that will result in their sudden disappearance/end.
Spergologists, if they're so inclined, generally don't need any help outside of just the person's name anyway. That is, if someone is genuinely interested in "researching" said sperg (presumably to post more entertaining anecdotes about their behavior) they don't need the farms to directly jizz it into every last crevice of Google.
It's sort of like hacking. When you discover a good exploit the very last thing you want to do is go around openly posting it because stupid nubs will just fuck it all up and it'll get patched almost immediately.