Why did Nana Patekar once refuse Raj Kapoor's film offer?

Late actor Nana Patekar once turned down Raj Kapoor's film offer, saying he couldn't disagree with his family's hero on set. He similarly declined Dev Anand and V Shantaram. Patekar won three National Film Awards and was conferred the Padma Shri in 2013 during his five-decade career.