Why bring MNK to anything anymore?

[Atreides]

No because you are not guaranteed to have a NIN in all of your parties, while the NIN is guaranteed to have trick attack in all of its parties. That's like saying parses aren't accurate because there is no selene there for buffs.

The fact remains that Nin work with a debuff that works for all classes and have access to it while parsing, so when a Nin does about the same damage as a Monk he will of course beat them because Monks do not have access to it.
On a parser it's easy to beat a Monk but if said Monk hits on the same dummy it's a whole other story.
If anything Ninjas beat monks in offensive utility.