Why not acknowledge?

With respect to an earlier post by Amit Verma where he mentions that two of songs created by Shantanu Moitra ("Pal-Pal from Lage Raho Munnabhai" and "Kaisi Paheli Zindgani from Parineeta") are directly lifted.
Similarly the blockbuster song "Bheegi-Bheegi from Gangster" by music director Pritam is a direct lift from Bengali rock band Moheener Ghoraguli's song "Prithibi Ta Naki".
The point is when you are lifting songs or infact directly copying any art why not acknowledge it while releasing your creation? That way at least there will not be a shadow of doubt on your other works.