Only popular ones get crap oned
this

on a more serious note, it`s mostly attributed to oversight, because if an add-on has such low quality that it`s failbinned, it should also be crap-on`d.
however, crap-oning is usually to prevent bad add-ons from messing up your game, and if you are able to fix it, you would be able to change the add-on`s name, too.