Well, this particular forum is "miscellaneous," after all.
I keep mine carefully clipped. I'm a male senior citizen. I believe an important reason for that is not just good grooming, but because one's piano teacher or others who see you play are really going to notice!
Also, it seems easier to keep the nails short for consistency. That way, the chords will always feel about the same under your hands.
We knew one woman years ago who had a beautiful piano, and had a reputation of being a pretty good amateur pianist, but didn't play because she had long nails and did not want to shorten them. Fashion won over musicality.
Speaking to the women out there, is it possible to play the piano with long nails? Is the only option to keep them clipped short?