One Foot in the Classroom

Why are there so many administrators that no longer teach K-12 students on a regular basis? Why are there so many professors in departments of education who no longer teach K-12 students on a regular basis? Why are there so many educational technology "experts" who no longer teach K-12 students on a regular basis?

I remember learning from professors like Maggie Lampert, Deborah Ball, and Glenda Lappen who at that time still worked regularly with K-12 students. What they had to say was so much richer, nuanced, and in the end practical for helping me teach in new ways!

Though I spend a great deal of my time working with teachers, I still have my own classroom part time and collaborate in the classroom with many others. The benefits definitely go both ways. I get to try things out in my own class and bring my experiences and examples to the table when working with the teachers. Their work in turn inspires what I try back in my own room.

Why would anyone ever completely leave the classroom?