I've often thought it was strange that one's value as a scholar is determined largely on the basis of one's research, yet one's ability to perform "good" (in quantitative and qualitative terms) research is based largely on the type of institution where one works.
Consider the following scenario: Scholar A gets a job at an R1 straight out of grad school. Scholar A therefore has a light teaching load, generous sabbatical, a large research budget and so on. As a result, Scholar A goes on to publish prolifically in top journals. Scholar A's professional profile rises. The university that hired him pats itself on the back for having made the right bet in hiring him, since, of course, he turned out to be a "top" scholar.
Scholar B, meanwhile, attended the same graduate institution as Scholar A, and wrote a dissertation that was deemed equally meritorious. Due to the vicissitudes of the academic job market, however, Scholar B ends up with a first job at a teaching-focused college rather than an R1. Saddled with a 3/3 teaching load and few opportunities for internal research funding or protected research time, Scholar B publishes little, and most of what he does publish is in second-tier journals. Even if he is a great teacher, he remains unheard of within his field, since status is determined mostly on the basis of research. Consequently, people who look at Scholar B's academic record ten or twenty years after his Ph.D. confidently conclude that he is a mediocre scholar, who would never have been fit for an R1 that hires top scholars.
This would seem unfair. Scholar B might have been just as productive research-wise as Scholar A, had the former had the good fortune of working at an institution that facilitated an aggressive research agenda. But Scholar B ends up being deemed "not very smart" because he produces little research.
In other words, it has always seemed to me that scholarly success is in many ways a self-fulfilling prophecy. The R1s that pride themselves on hiring "top" scholars don't actually pick or attract the right people as much as they create the conditions that allow one to turn into a top scholar (in a world where, again, that status is based mostly on your research).
I happen to be a tenured faculty member at an R1 university, with a publication record that I am quite proud of. But I'd be lying to myself if I said that I would have published as much -- and earned the reputation I have in my field -- if I'd spent the years since my Ph.D. working in a more teaching-heavy place.
I'm also in the humanities. I'm not sure whether the trend I describe above exists in the sciences.