Gary, capacity for two and arranger equipment is there, it's the
speed that's the problem. 
Got used to 200 plus knots, so when I fly, I want to go at least twice as fast as I could in a car or truck. 
Just got too much to do, and it's not easy working in a 180 that's being blown around a bit.
Then, there's the increased weather sensitivity as the plane gets smaller. 
r.