The problem via Allahabad is not only NCR but Asansol and Durgapur too, they're way too congested to handle any additional trains that's why Kolkata has been getting new connections via SER mainly (with exception of Sealdah Jammu Humsafar). Although I totally agree that Allahabad route would've provided All year patronage to Humsafar had it been there.
Rahi baat Time Table ki toh I still happy with it because when I first heard about Habibganj Santragachi Humsafar I was fearful about its time table especially after seeing time table of Tirupati Humsafar and Champaran Humsafar ЁЯЩП, it's still way better than those two if not best. рдбреВрдмрддреЗ рд╣реБрдП рдЖрджрдореА рдХреЗ рд▓рд┐рдпреЗ рддрд┐рдирдХреЗ рдХрд╛ рд╕рд╣рд╛рд░рд╛ рд╣реА рдХрд╛рдлреА рд╣реИ, Bhopal desperately needed a connection...
more... to Kolkata I'm happy that atleast it got that essentially that too in time.
Regarding Humsafars I expect the worst time table only so after seeing time table of Allahabad Humsafar, Habibganj Pune Humsafar and some others there is still hope regarding speed in Humsafar trains.