Why was Tarkhad's son hesitant to go to Shirdi with his mother, even though his father wanted him to?

According to the narrative in Chapter 9, Tarkhad's son was a devout devotee who performed daily worship of Sai Baba's photograph, which included an offering of 'Naivedya' (food). He was worried that if he left for Shirdi, this regular worship would not be performed at home. His hesitation was amplified because his father was a follower of the Prarthana Samaj and not accustomed to idol worship, making the son wonder how it would be right to entrust this sacred duty to him. This concern was described as a "great puzzle for the son."