Not sure what you mean by "Corps administration", but if you're referring to the commandants then I don't think that's true. In my experience, Jackman officials were very pro-athlete when it came to Corps leadership positions, President Schneider in-particular. I know my senior year the Regimental Staff had at least 5 athletes on it (2 baseball, 1 women's rugby, 1 swimming, 1 cross country). And then 3 of the 5 battalion commanders were athletes (baseball, women's rugby, swimming). I think some sports have inherent advantages when it comes to placing people in leadership positions, such as the spring sports. This is especially true when talking about freshmen or Rook leadership positions, as the nature of Rook Week and the beginning of Rookdom being the most intense portion requires a time commitment that is difficult for Fall athletes to fulfill.
If, however, you're referring to actual Cadet leadership, then I think this is absolutely true and depends on the year and the leadership. Again, from personal experience, my junior and senior year I think great progress was made in improving Corps-athlete relations and Corps involvement at athletic events. But, the year after I graduated the new Regimental Commander had different priorities and a negative perspective on athletics and pretty much erased all the progress (except for, ironically, club hockey).