Because in the beginning of the story postmaster 's behaviour towards Ali was very rude. he used to just throw the letters after inspecting them without thinking about the value of that letters..... that's why at starting postmaster does not deserve any appreciation from reders

Postmaster's Lack of Appreciation
The postmaster does not deserve the reader's appreciation in the beginning due to several reasons that are evident in the story.

Lack of Empathy
The postmaster shows a lack of empathy towards the young narrator when he first arrives in the village. Instead of welcoming him warmly, the postmaster seems indifferent and detached, making the narrator feel unwelcome.

Exploitative Behavior
The postmaster's exploitative behavior is also a reason for his lack of appreciation. He takes advantage of the narrator's vulnerability by offering him a job with very little pay and making him work long hours, without considering the narrator's well-being.

Unfair Treatment
Throughout the story, the postmaster treats the narrator unfairly, expecting him to work tirelessly without any recognition or reward. This unfair treatment further diminishes the postmaster's likability in the eyes of the reader.

Manipulative Actions
The postmaster's manipulative actions, such as using the narrator's loneliness to keep him working at the post office, also contribute to his lack of appreciation. Instead of fostering a genuine connection with the narrator, the postmaster manipulates him for his own benefit.
In conclusion, the postmaster's lack of empathy, exploitative behavior, unfair treatment, and manipulative actions all contribute to why he does not deserve the reader's appreciation in the beginning of the story.