There is merit in your argument. But there is no guarantee that the IB report came before all this happened. It may have been in hindsight! Otherwise, you can say the present home minister also slept on these reports.
This report may be half baked, or some body thought the loss of votes will be too much if they acted. This happened when the police in Hyderabad were aggressive in their approach to get to the bottom of the blast cases there.
The politicians, you know who, made the police go soft. And that was the end of that investigation.
