I can't speak for other realms but this is what I've been noticing on my server. The first class that seems to fill up for every pf group seems to be blm.

I originally played a blm cause vivi from ffix was one of my favorite characters from the ff series. But I've been kinda disappointed with their one dimensional rotation and their somewhat poor sustained dps and have since switched to summoner.

So what is your reason for playing a black mage?