I don't think it's that much of a crime to call a piano song "a piece"
I do bealive it is the most beautiful piece ever written, so I don't feel regrets calling it that
but even if I didn't it's youtube, people sometimes use catchy titles, no need to go insane about it
I undrastand that you're trying to help, but that's not how I'd define support.
same with reason three, yes, I make jokes, yes, I don't explain every little thing like a harvard composition teacher, again
it's a youtube video