U are slightly right!!!
If u compare schedules, u will find it hasnt remained constant, but have fallen down for many trains!!!
And adding upto it, the actual running has further been degraded, imposing TT just a mockery of practical/actual scenario!!!
Some of many Reasons:
1....
more... Conjestion
2. Unrequired Stoppages
3. Political Influence for increase quantity not quality (Infra & Rakes)
4. Disastrous Management - Historical System Prevails in IR Mechanism
5. Unequipped & non-skilled ground level Laymen, who actually runs trains
6. Increased capacity of Goods Train, without Track Modificaion, resulting in caution-posed running (upto 60KMPH on trunk routes) & if run faster, either collides or derail
7. Non-availability of Bye-pass for goods train, in major Junctions
8. Non creation of SUB-Trunk routes (eg, Shikohabad-Farrukhabad-CNB/LKO-Sitapur-Roja as superb back-up for Goods Trains)