I have some sympathy for the judge here. Though a sentence of one million years hard labor followed by summary execution is probably the correct one for a case like this, Gattani could change. He could be somebody who pays his debt to society, gets counselling, makes positive changes in his life, and goes on to have a healthy positive relationship with his daughter and the world. Keeping the case in the USA allows the court to stay involved and that might lead to the best available outcome for the victim and her child (aka victim #2).
If the judge were to impose a harsher sentence such that deportation post-sentence was mandatory, Gattani would then be outside of the judge's jurisdiction and the judge would have lost any ability to monitor the situation or get the best outcome for the victims for any future crimes Gattani commits.
In India Gattani may well have situation management options not as readily available to him in the US, because of the money he has, how much further that money sometimes goes in India, i.e. his ability to pay bribes, the degree to which corruption is present in the Indian judiciary [1][2] and police force [3], and differences versus in the USA in some parts of Indian society in respect of attitudes to spousal abuse, appropriate punishment, and to divorce. The availability in India of options which allow Gattani to avoid taking responsibility for his actions might act as an impediment to real, substantive, changes by him.
On the other hand Gattani got a minor sentence for a terrible crime. I sympathize with the victim here one million percent when she makes that observation. But its a judgement call by the judge and arguably there are no great options here because the best short term options and the best long-terms options are in conflict.
No matter what happens in future Gattani has to live with the knowledge that he abused his wife and his daughter. Its not an easy road for him from here no matter what. He has been publicly shamed in the media, and now he is a convicted felon without a green card. Good luck getting one now. Over and above the sentence itself imposed by the judge, these are consequences for Gattani of that sentence, and ones which the judge almost certainly aware.
[1] https://en.wikipedia.org/wiki/Judiciary_of_India#Judicial_co...
[2] http://lmgtfy.com/?q=indian+judiciary+corruption
[3] http://lmgtfy.com/?q=indian+police+force+corruption