To maintain RSA.
Plus no congestion towards Nizamuddin Side
Only trains towards Meerut and Freights using ANVR NZM Line.
Can be easily introduced via Kanpur
Problem in the proposed route via Kanpur won't be Nizamuddin....
more... As long as RSA is kept and NR doesn't need to arrange for something extra it won't mind whether train comes from Palwal or Ghaziabad - NR anyway has to give a Platform at Nizamuddin which would be the main concern. Direction won't matter.
Problem would be reversal at Kanpur, NCR simply won't take it.