isn't considered by what rule? LMAO.
it's not any hard rule - just what i've noticed from past remake songs. IU's "meaning of you" was one of the biggest hits of 2014 but it wasn't seriously up for SOTY (even tho it was nominated) because it was a remake.
unless you can find a single remake song in history that's won SOTY....
it's similar to the unspoken rule that collabs and features don't really win SOTYs either. I think the only exception was "boy with love" but the feature wasn't with a korean artist. You're also welcome to try to find any collab songs that won SOTY. these are just my observations as someone who's followed kpop since 2010.