Because nature is a poor translation, if we go by nature then the men are always the pretty ones..lion manes , peacock colors, longhorns, colorful fish..the word Paul used is more like social norm or custom not natural order

It is Paul, his own bias as a bald man, and having a hard time letting go of OT/Judaic law style subjugation. Like he might as well have said "well guys, remember when the big man said we can eat pork and shrimp now....well, nah, I just um..heard from Him that they are still off the menu!"