Do you blame The Postmaster for his decision to leave without Ratan?

Yes, I have no problem blaming the postmaster for what he
did to Ratan.  I try not to speak in absolutes, as a rule, because there are always
different levels to individual action.  Yet, I do believe that the postmaster does
deserve a great deal of blame for abandoning Ratan.  I think that Tagore does an
excellent job of showing the love that an orphan has for someone who gives a fragment of
human emotion. Ratan suffers from a typical abused child condition.  She shows absolute
loyalty and devotion to one who shows even the slightest of affection towards her.  In
this, she demonstrates complete dedication to the postmaster.  She attends to his needs,
takes care of him when he is sick, and does not ask for anything in return.  His
teaching her to read and write was only to sustain his time there and not be bored. 
There was no other reason for him to do this.  She repays this debt and then
some.

When she asks him to take her with him, his reaction
of laughing is indicative. The postmaster does not even show her the slightest of
respect in acknowledging her request with a response.  He dismisses it, and, in the
process, dismisses her.  In this instance, Tagore shows the fundamental distinction
between those that have power and those who do not.  At that moment, Tagore displays
what it means to be an insider and what it means to be an outsider.  It is within this
singular entity that the postmaster's character is on display.  When he offers her money
at the end, her need to run away is a representation of so much.  The sadness, longing,
and shame of being treated as nothing more than a servant is what strikes her.  He does
give her at least the decency of a thought while he is on the boat.  Yet, his
rationalization that hearts are broken and people suffer as a fact of life does little
to console her.  If nothing else, it is an excuse for him to not have to face the
consequences of his actions of abandonment.  It is here where I sense that there is
blame for him to be given.  It is here where I think that Tagore elevates Ratan to a
heroine status.  The fact that her wandering around the village in the vain hope of the
postmaster's return is a reminder to the reader that at some point in one's life, one
will feel the sting of abandonment as Ratan does.  At least for an instant, Ratan is a
central figure.