Nationwide bit the dust so resources could also be diverted into starting up Breakfast Time..
Well, I wonder, because the replacement, 'Sixty Minutes' came from the same Lime Grove studio as Breakfast/Nationwide, and still required broadly the same level of resources as NW ?
The BBC wanted a different feel to their early evening programme, and Nationwide just felt like a dinosaur. The format was also rejigged many times, that a fresh start was needed, which the BBC felt Sixty Minutes could provide.
Also, Nationwide did have a varied slot in terms of its length per day. Sixty Minutes would be a regular fixed slot for the BBC to work the rest of their schedule around, as the name made it clear it was on for an hour at maximum.
Poor London and the South East news though on both Nationwide and Sixty Minutes. When Sixty Minutes started, even the South East at 6 name was dropped and was just named "South East".