I just read an interesting article mulling over the reasons why many intellectuals oppose capitalism and the military. The essence of the argument is that intellectuals get used to being the best while in school. They then are offended by institutions which reward skills and behaviors other than those school rewarded. Capitalism and the military often reward courage, daring, and single-minded effort; on the other hand school tends to reward inherited intellect (high IQ).
Studies have shown that college grades generally do NOT predict future success in business. I'm not aware of studies focusing on grades as predictors (or not) of success in the military, but perhaps a reader may be able to suggest a source.
Full disclosure: I am an intellectual and I favor both capitalism and the military. However, I realize that, among intellectuals, I hold minority views on capitalism and the military.