Because they are totally worthless.

It's clear that, just like everything else in the rushed Zadnor, little thought was given to the rewards you could trade them for.

I have 200+ Plat Coins and 500+ Mythril Coins and the only thing worth trading them for is Early To Rise haircut which price plummeted after Zadnor came out.

The gear is worse statwise than DRS gear and looks out of place compared to the previous gear's aesthetic.