Board Thread:Council of Arrowverse Wiki/@comment-9346948-20180119051714/@comment-27700324-20180122195034

Stryzzar wrote: Not every Kryptonian is in the situation of Kara and Kal-El. While it's true all Kryptonians could potentially have power loss due to red sunlight, it would only be a problem for Kryptonians who had absorbed enough solar radiation.

This is like saying we should remove coldness from Barry, Eobard, Zoom, and Savitar then moving it under a general Speedster weakness. That is why you only put that weakness on the Kryptonians on Earth. Also even when you have absorbed a small amount, you can lose it to red solar rays.