I like the must-do aspect of commuting. I was riding if it was raining, windy, cold, dark, icy, smoky; if I felt like crap, lazy, sleepy, sore; if my first meeting was at 9:00 or 6:30. At the end of the day, same thing - no choice. It was part of my identity, corny as that sounds.
I can't duplicate that must-do feeling with recreational rides, or even utility rides.
The dark/rain/cold stuff sucks.