Taurog is also bloody powerful with classess that otherwise require quite a bit of thought and experience to either figure out or play. Any taurogzerker variant (monk or berserker) is single-minded and makes reading the board hugely simplistic while at the same time making you powerful - glyphs? Convert! Monsters? Click on! Shops? Bah, who needs them, I prepped fine sword and Taurog's filling my inventory anyway! Spike? Taurog's got it covered!
You can't actually play a Berserker or a Monk that way without serious end-game preps. And what's more he's not just a piety farm, he's a really explosive piety farm which sinergizes with converting everything in sight. He's be popular even if he unlocked later, I bet
(Plus, without all the shop upgrades and item unlocks, and not very good grasp of glyphs, his "fills up your inventory" feature is pretty glorious - if you take all 4 you also get a dwarven gantlets which take no slots, and a DP spike option to top it off).
But still, he doesn't really work with spellcasters, and Binlor beats him hard for damage (and he does work with PISORFF spellcasters). I can understand why Taurog's popular, but I can't even immagine all the implications of Binlor not being popular.