Random loot is random, and no individual is likely to have done anywhere near enough runs for their experience to be even remotely statistically significant.

Personally it's been raining tank drops in WOD for me - I've got all 6 after having been running my PLD through the place for less than a week, and during that time there were constantly duplicates left to go on greed rolls. But on the forums you also hear people saying they've gone 40+ runs without a single tank drop.

The fact that the drops are split up unequally might also make some drops seem more common than they are - bosses have 10 or 11 drops each, and drop 1 or 2 pieces for each class. So for a boss that has 2 drops for a class you're uninterested in out of a pool of 10, tat class's drops might seem more common than the others.

http://ffxiv.consolegameswiki.com/wi..._Darkness#Loot