Why are there mortals in exalted?

[golentan]

I ask because there is 0 reason for the mortals to not all have (at some point) received enlightened essence, and the benefits to a society that practiced it would be insanely tremendous.

I ask because I was going through Scroll of the Monk, which introduces the charm Soul Enlightening Beneficence, and makes it clear that all celestial exalts have a variation on it. It grants enlightened essence, a mote pool, and the ability to learn charms of the exalt type that enlightened them. The fun thing is that the requirements to learn the charm in question are within reach of a heroic mortal: Given 60 experience (about 6 years of training), they can pass it on to other mortals at the cost of a few hours and some effort for each one.

This seems like the sort of thing the Thousand Stream River would thrive on: with the massive availability of charms, empowered thaumaturgy, sorcery, supernatural martial arts, and more a society could easily trounce its neighbors, negotiate with gods, hold back the fey, battle the deathlords, and hold their own against realm and dragonblood influence in large part. Each mortal would be weaker than the weakest exalt individually simply by virtue of the size of their mote pool, but there would be a lot of mortals with celestial level charms. I find it hard to believe that not one of them tried this at any point in the last millennia and a half, and I find it hard to believe such a project would just vanish into the mist.

[Tavar]

It would be extremely noticeable, and likely counter to two of the major ruling bodies of the time(the dragonblooded and the Sidereals). Not to mention that Creation supposedly resists having large numbers of Essence using humans around.