I use to single hand 95% of the time. Why?
When the Admiral comes, we can't heel more than 5 degrees, and have to be back in 2 hours.
When experienced crew comes along, I feel like I need to share the helm duties. Maybe I am antisocial.
This season, the Admiral graduated to first mate...can now stand 15 degree heel without white knuckles, will stay out more than 2 hours (but still no overnights), and has been a big help docking. We moved into a new slip this year, and I am still struggling to find the right approach (but haven't hit anything yet).
Biggest reason is that if the weather is OK, and I have the time, I am going sailing...not going to worry about finding someone to go with me.
Greg