The issue is really about work load...can your typical pilot hand fly an aircraft and not be overloaded during that task that he can still determine where he is, where he needs to go, and get there safely..
As the automation has increased, the lower pilot standard is to accept a lower and lower cockpit workload...make it two pilots and everyone is clamoring to be the guy that gets to move the heading bug....
So it's no wonder that with all the automation..the FE has gone bye bye and people consider dumping the FO who has become a seat warmer.
Trust me..if it's all about redundancy now...just throwing enough people or gear in the cockpit to make sure the flight makes it to it's destination...then airliners will go single pilot with a UAV pilot on the ground monitoring numerous flights ready to take over, should the heart monitor of one of the captains flat lines, or he doesn't respond on cue.