I like routine, not because I'm a boring person (actually, I am). With routine, I can plan my other ad-hoc activities around these fixed activities.
If I live by the day, then how am I supposed to plan activities for tomorrow, or next week, or next month?
Routine allows you to find a match with your peers over a period of time. If my friends have routine, then it's easier to plan ahead to meet. For friends with no routine in their lives, it is impossible to meet them. They are either busy with activities that come their way at the last minute, or they would say they are busy with activities that are expected to come their way.
Then again, to them, being busy is a routine for them. Perhaps, when they become idle, they would feel uneasy and unplanned.