If your argument is that white students are more interested in college sports than black students, I disagree. When I attended (granted it was in the "glory years") black students were very interested in the basketball team. I don't think there is any difference in the races in proportion to their relative population on campus.
I do think that there are other factors which may play into the disparity in attendance. First, I think there is a much higher white population than black in terms of resident students. That is due to socio-economic factors. Students who live on campus tend not to work, whereas commuter students tend to have after-school jobs.
If you look only at the season ticket student sections, they are mostly white but there are a large number of non-white students throughout Carnessecca. The Garden, maybe not so much. Again, socio-economic factors.
If race were the only deterrent to student attendance, then you would have CA full of white students; and the Garden would be more packed with them. Students are kept away for a variety of reasons, not the least is the culture of losing that we've fallen into the last 10 years. St. John's is still majority white, therefore it is not surprising that student attendance would be majority white.