Not necessarily that they're not taking time for leisure purposefully, but that they're "pre-occupied" with the daily grind.
Occupied by activities which pull one away from the fullness of enjoying life - these could be activities of the mind or actual activities which feel unfulfilling. If your mind is always processing all the little things you need to do next, in a subtle kind of "worry"..."I've got to do this, I've got to do that"...and these thoughts make it difficult to savor the present moment. It is almost as if joy is a very subtle experience and the complexities of civilization are so much more noisy and make it difficult to look for and see joy. If you combine this one with Vatican Saying 11, then it fleshes it out a bit more (at least in my mind).