Why are monks consistently lowest damage in CC?

[Iyrnwaen]

I keep seeing it over and over again..matches with anywhere from 500k-1 million damage dealt and then monk just sitting there at 300k. All different players at medium levels. Is monk really that bad?

MNK isn't bad at all. It posts lower damage numbers because it has no poke and virtually zero incidental AoE damage.
MNK is a competent single-target brawler at all times, and a deadly assassin when its ult is up.
Total damage isn't a particularly meaningful stat, especially if you're comparing one job to another instead of comparing, say, two MNKs in the same match.
SCH can easily deal double or triple a MNK's damage over the course of a match, but it's irrelevant because it's all DoT padding.
By the same token, BLM and NIN can get their best total damage numbers by playing the jobs completely wrong.