I suspect no one thinks it would be marketable or successful. I wouldn't bet my money on such a movie. <g>
They re too scared. Maybe.
Besides, it doesn't have a real ending. Decades of unchanging imprisonment don't make for good drama. If and when he gets out, then maybe someone will deem the subject worthy.
For more on the subject, see The Best Indian Movies.
P.S. I've made minor changes to Krogh's messages to make them more readable.