Sir,
This is illogical but TRUE. The fear of reporting much trains delayed, would have prompted IR to adopt this practice. I agree with you that the time is important but IR considers importance of time for select train passengers only.
Fact is that the so called Slack Time is not provided only before the terminating station but also in between just for the fancy o f showing the trains on time. Keeping in view your contention that even after this, the trains are delayed, I am of the opinion that the...
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IR must come out of this fear and remove all illogical slack time durations.
On the other hand, I wish to mention that slack timings enroute (not just before the terminating station) become the reason of ultimate delay in many cases as even when a train does not utilize slack time enroute, it has to be detained till that margin exhausts and thus time is wasted there. Had that time been saved, that would have compensated the delay in the last leg and thus, even after getting delayed during the last leg, the train would have taken the (existing) duration only.