There is a famous story about Sigmund Romberg in a card game with, I think it was, Jerome Kern. Kern signaled to Romberg to play the ace by whistling one of his tunes, "One Alone". Siggy didn't get it and lost the hand. Kern later said to him, "I whistled "One Alone" to you and didn't you catch my message?" Romberg said to him, "Who listens to the lyrics?"

This might have been typical of the composer of Desert Song. The Operetta
in those days was not given to social issues which were largely ignored as were the lyrics by many composers who saw them as window dressing for their tunes.