Why do research faculty pursue administrative positions, such as dean, provost, president, etc. ? Do such positions spell the end of one's research?
In these positions, one gets to influence the direction of the whole university, rather than the direction of the research of 1 to n individuals. At such magnitude, one can effect more change. 

Often people get disgruntled with the way things are run at the level they are currently working. The only way to fix things is to move to more managerial positions. Don't like the way the Masters program is run? Become Coordinator of the Masters Programme. Don't like the way the faculty is being run? Become Dean.