For our analysis, it's the mean and not the median that matters, since we're talking about the sum of money brought in by professor teaching divided by the number of professors.
From first glance, it looks like the median is quite possibly below 25, but the mean isn't, if you only look at undergraduate courses.
Also, professional schools have huge class sizes and charge tuition at the same or an even higher level.
The grad courses of course have smaller class sizes since they're the long tail of education, but that's not what we're talking about here. If you remove the courses with 0 undergrads, the average is probably not below 25.