Couldnt the creatures that are using it be changed so they no longer have the feat?
Not quite sure what you're saying here.Its part of their build and balance? You want people weapons being put to the ground?
We can't change bioware-standard creatures? Sure you can... replace the creatures doing the disarm that drops things to the ground with ones that work properly, made by us. Or find the balance you want via another build path not using disarm..