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.

[Gserpent]

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.

The AOE DoT isn't really padding, though. Even unbuffed it's essentially sapping a Recuperate from everyone it hits, plus the damage down. Buffed up, you're looking at 25k damage, and up into the 30k range if there's a BRD or AST around. SCH is an attrition/pressure class. They focus on fudging numbers in their team's favor with constant overshielding and damage buffs and debuffing the enemy team. SCH rarely gets kills but their pressure output is intense.

[Iyrnwaen]

The AOE DoT isn't really padding, though. Even unbuffed it's essentially sapping a Recuperate from everyone it hits, plus the damage down. Buffed up, you're looking at 25k damage, and up into the 30k range if there's a BRD or AST around. SCH is an attrition/pressure class. They focus on fudging numbers in their team's favor with constant overshielding and damage buffs and debuffing the enemy team. SCH rarely gets kills but their pressure output is intense.

Damage that doesn't lead to kills is padding. I'm not dumping on SCH. The thread isn't about whether SCH is a good job.
The thread is about why MNK's damage numbers are low compared to other jobs.
Other jobs post higher damage numbers than MNK because they have more incidental, non-lethal damage in their kits,
and SCH is the king of incidental, non-lethal damage.
SCH's kit is aimed at creating an EHP gap between the two teams. MNK provides single-target pressure and then blows up one guy.
Total damage is the worst metric you could use to compare them. That's the entire point.