Small Classes: Great For Ivies, Not For Children?

The eldest Jazzboy is a high school senior, and he's pretty bright. Which means we've been looking at colleges - a lot of colleges. And you know what?

The most elite colleges all brag on low student-to-teacher ratios and small class sizes. Take the Ivies:

Harvard:
The faculty is highly accessible, and Harvard College class sizes are on average below 40, with over half the courses being offered each semester enrolling 10 or fewer students. This allows for a closer student-professor relationship and contributes to the sense of community on campus.
Yale:
“Average” can be a very misleading term. Classes at Yale range from one-on-one tutorials to small seminars to lecture courses of several hundred students. Seventy-five percent of Yale College courses enroll fewer than twenty students; twenty-nine percent enroll fewer than ten. Only about forty out of all 2,000 courses enroll more than 100 students.
Princeton:
The student to faculty ratio at Princeton is 6:1. From freshman seminars to senior theses, faculty are deeply engaged in undergraduate teaching, and they are readily available to students outside the classroom for individual conferences and informal conversations. 
 Penn:

Faculty (as of Dec. 2011)

Standing: 2,532
Associated: 1,714
Total: 4,246
Academic Support Staff: 2,347
The student-faculty ratio is 6:1
Brown:
Other facts will impact the quality of your education—such as our student-to-faculty ratio of just 9:1 and the fact that 100% of our faculty teach undergraduates. You'll also be interested to know that 70% of our undergraduate classes have fewer than 20 students. That means you'll have a lot of face-to-face time with some of the best researchers and teachers in academia. 
Dartmouth:
How did you end up at Dartmouth?
I did a summer program at Columbia University during my high school sophomore year and knew right then that city schools were not for me. I fell in love with Dartmouth when I visited and sat in on a class. I loved the small class sizes and the professors who are passionate about teaching.
Columbia:
80% of undergraduate classes taught at Columbia have fewer than 20 students. Since Columbia’s Core classesare small seminar classes and since more advanced courses are meant to allow direct connection with faculty, few courses at Columbia are larger than 20 students. Those classes generally are either popular introductory lectures or upper-level classes in especially great demand.
Cornell:

 
We have tons of research that shows class size is important for children in K-12 schools. But even if you try, like Mitt Romney, to dismiss it all...

Doesn't it say something that class size matters to our nation's smartest 20-somethings?