Rockfort Express: திருச்சி அவனது கோட்டை, இரவில் சென்னை வரை வேட்டை, அவன் தான் மலைக்கோட்டை. - Vijay Baradwaj

Why shouldn't they? They are travelling in Rajdhani for a reason - They want to reach their destinations with minimal delays with topmost comfort and speed. If they didn't wanted to reach on time , they wouldn't shell out extra money.
Sealdah Duronto is a Duronto, a class above Normal SFs with higher MPS. If you can justify the OT of Rajdhani by A normal SF, then OT by Duronto should be easily justifiable.
Regarding the DRM twitter handle, it was brought into existence to listen to...
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the problems of people(pax) and provide a solution to them. No use of them if we can't put forward our problems. We have been given this right to question and hence we will. I am sure you would have also done the same if something similar happened to your favorite train.