I write this as a Western person with no real knowledge or bias regarding the Hindu religion, Islam, or the people involved in making this film.
The story seems to centre on "Romeo and Juliet"-like themes of "forbidden" love - certainly not an earth-shattering, ground-breaking movie theme. Some of the characters are, to me, overblown; the mother's histrionics about her daughter's affair with a Muslim, the son who behaves wildly and inappropriately at a Holi party, the daughter-in-law who melts down the father's medals for earrings, and the corpulent sultan who seems to revel in causing conflict.
Certainly the scenery and cinematography are exquisite, but I found the story somewhat difficult to follow at times. I chalk this up to my not being a part of the target audience. I did not really understand the significance of the songs and poems. I don't know how the parliament/city council/legislature depicted here works or is constituted. I don't understand the nuances of how people dress for various occasions. I did not grasp that a kiss in a temple was so significant. Other productions about India (Jewel in the Crown, Gandhi Slumdog Millionaire) made these kind of things clear to the Western viewer, but A Suitable Boy seems to have missed that mark.
I don't know and can't comment on whether or not the show was pro or anti Hindu, only on whether or not I understood and enjoyed it. That seems to boil down to a 50-50 split - some parts were good, some were not.
