Pretty much what @insanedreamer said. This is why US News sells so many magazines every year - their ranking scales largely conform to what people are expecting to hear about universities and colleges. US News’ rankings are very reliant on inputs - the perceived quality of the students who go to the school. Bloomberg very clearly laid out their methodology and their criteria are all outputs - where students end up after college, and how they feel about the college once they are already there. Depending on your values, you may value one ranking over the other. Personally I think it’s better to evaluate a university in terms of where it places you in your career than what you looked like when you got there. But that’s just me.
Why do you think that? I’d be interested in your reasoning. (Genuinely.)
Graduate departmental rankings don’t indicate anything about the undergrad alumni network in a specific field. The graduate alumni network may not matter as much, either, if most grad students end up in academia.
Graduate departmental rankings do allude to the quality of professors, but the quality is related to the professors’ research output and ability to get grants. That has, in my opinion, a net neutral effect on undergrads. On the one hand, additional grant money flowing into the department increases the resources available and may create paid research positions for undergrads; also, having experts in the field teaching you in class is great. On the other hand, a lot of those hotshot experts only teach graduate seminars (or don’t teach at all!), and more grant funding also means that adjuncts and teaching assistants are hired to replace the professors who are now doing research to sustain their grants. Also, having to concentrate on grant funding means that professors spend less time concentrating on teaching and mentoring. That doesn’t mean that they are bad at it, or don’t care about it - a lot of professors do like it. But it does mean that on average they are far more occupied by their research agendas than teaching undergrads.
In my prestigious graduate department, lower-level introductory classes were taught by adjuncts and lecturers who were hired specifically for that purpose. Mid-level classes (sophomore and junior level) were taught by new assistant professors who were on the tenure-track - great researchers, but early career. Upper-level seminars were taught by new assistant professors and a few of the tenured professors, who sometimes taught one upper-level undergraduate seminar. The real famous experts in the field mostly taught one graduate seminar a year. (There was one very famous professor emeritus who did teach a mixed undergrad-grad class.)
I also think the research opportunities are a net neutral. On the one hand, there’s cutting edge work going on, and undergrads may have the opportunity to work on something really cool! On the other hand, scads of grad students and postdocs mean that undergrads are lower on the pecking order, and the tasks that they do may be more routine than actually fully participatory.
That also doesn’t address the fact that many college students will change their major anyway, or that most of the classes you take are not in your department.
Still, I will revise my original statement. You’re right - it’s not that they’re not important at all. That’s too strong. Rather, I think they should be pretty low priority in any college-bound senior’s criteria for a university.