I would rather think the airline pilots don't want to re-program the FMC/ CDU while in flight, everything is set-up before they even start....
I remember a pilot who needed 5 minutes at SFO to change from 28 left to 28 right only.... (this was for departing though) so, to change the runways for landing would give more workload.....
'Stepping over' to parallel runway for landing is no big deal. All you have to do is enter new ILS frequency in CDU. Can be done in 10-15 seconds...here's the button sequence on CDU for Boeing:
1.) NAV button
2.) Enter new ILS frequency (confirm with other pilot)
[this sets new ILS runway for LOC and GLIDESLOPE]
Or, you can set new runway ILS via ARR button by selecting STAR + new runway via side selector buttons next to CDU screen, confirm, then Execute. Then go back to NAV display and press the side button that corresponds to the new ILS frequency which should be automatically displayed, but not active. Pressing button activates new ILS.
Either way takes about 10-15 seconds for non-flying pilot.
Not sure why it would take 5 minutes to switch CDU from 28R to 28L departure at SFO. CDU re-programming can be done in 20-30 seconds for runway switch. No departure SID for KSFO — including the quiet routes at night — require any changes between 28R or 28L (both runways use identical departure routes to first waypoint of all SIDS).
What might take a while is after switching runways, you have to do 2 things:
1.) Switch to MAP mode and cycle through each new waypoint using the LEG command and confirm with both pilots. After confirmation, you then EXECUTE. Figure 20 seconds.
2.) Re-program ILS for 28L (or 28R), since ILS is also used for maintaining runway alignment and hand-flying after rotation until autopilot 'grabs' the route.