As I said in a different post, my dad is involved in development for our alma mater. Without a doubt, 99.9% of people would rather have a top-notch Academic School with a range of extracurriculars then find success on the athletic field. Athletics are the most external showcase a school has, so what happens inside its doors are probably not well knowing to non-students an alumni, so I think people put too much emphasis on athletic results as the end-all-be-all of why these schools exist.
A quick Google search will find this conversation has happened in a majority of States at some level. What that tells me is one of two things. One, that every Catholic School somehow recruits to the detriment of their financial situation, or two, there's something about the socio-economic factors of upper-middle-class people that result in athletic success.
Everybody at a private school wants to be there. Because they're paying for it, most families go above and beyond to ensure their child has a more than adequate time at the school. Whether this is marching band, Athletics, Science and Technology programs, Odyssey of the Mind, Etc. They generally do pretty well.
A public school, Apple Valley, won 23 out of 34 state wresting championships, including 10 in a row. Either that school and the alumni support the wrestling program to a considerable degree or people move to the district if their son is a good wrestler. Are you suggesting that something illegal or immoral is afoot because of their athletic success?