I would say that MSF serves a different purpose. They create long term stationary projects. That has inherently less travel, even for a larger number of people.

I would say that MSF serves a different purpose. They create long term stationary projects. That has inherently less travel, even for a larger number of people. I think another commenter (zimzam) hits the nail on the head. While I'm against flouting travel spending rules, I do think it also depends on the type and level of productivity expected from the person traveling.