If it's so good, why 5.8?

Because it's a very badly made and also rather badly scripted film.

The characters are hollow, the acting is bad (Naseeruddin Shah's accent changes throughout the movie and at some instances seems incredibly put on) and the editing is shabby.

Jag Mundhra is a B movie director, and can not help put in some B movie scenes in the movie (the scene where the teenager is making out with his daughter; where he puts her hand on his pants (with a cut to his crotch to make sure you don't miss it)).

It's an attempt at painting an image of a current situation, but has a very superficial feel to it overall.