A lot of that depends on the job and the type of people involved. I once supervised a small group of computer operators. The work was more interesting than factory work, say, but it did get a little tedious after awhile. I could not trust them to work when I turned my back. Heck, I couldn't even trust them not to pop down to the local bar if I took the afternoon off.

In my current workplace it's mostly theory Y. But it far more easy to get excited about the work.