There's two important differences between /borg and /ignore: the latter lasts indefinitely, while the former expires after 15(? I think) minutes. And the important difference is that a /borg is a tangible admonishment. A monk who is the subject of thousands of /ignore's might still not even notice - not so with /borg. Sometimes, rarely, people do get far enough out of line that a slap on the wrist is called for.
The question, really, is whether those who have been given the power to /borg are responsible and impartial enough with it. tye may not have been; I don't know. At any rate, so far I have been witness to very few /borg's even though I am a frequent visitor. I don't think we're looking at a big abuse of power issue that would warrant doubting the feature's value. Feel free to disagree, of course; I'm only speaking from personal observation.
What I can say is, remember that /borg'ing is temporary. You did acknowledge you were not in the most rational of moods - maybe a /borg was not really justified, but it wasn't completely uninvited either. So - not a big thing really happened, in the grand scheme of things. I tend to be very sensitive to issues of power abuse and irresponsibility but this seems to have been an isolated incident, so let's just chalk one up on the crap happens board and get on with life.
There's more important stuff to worry about :)
Makeshifts last the longest.