This may be a bit of a rant, but nonetheless.
The LSAT drives everything. It's crap, but it's true. Law School Rankings matter, because law school rankings play a significant factor in both the incoming class and the interest of employers. Schools understand this, so they play the rankings game.
Here is how the ranking is calculated: http://www.usnews.com/education/best-graduate-schools/top-law-schools/articles/2012/03/12/methodology-law-school-rankings
As you can probably see, the ranking system is incestuous. Employers hire from the school with the best students, the best students go to the school with the best employment prospects, and the schools that pump out the most prestigious lawyers get the best peer assessment.
As rankings go up, students and employers are attracted to the school. But its pretty clear that what everyone wants are the best students (not necessarily the best-trained students) Because the scores are relatively tight between #25 and #75, every point matters, and admissions offices have little immediate incentive to bring in someone with a good career. They'll use those "soft" factors as a tiebreaker, but they will almost always choose a 163/3.6 with a job at quiznos over a 158/3.1 with an impressive management career.
I think the main reason why is that employers and schools are terrible at evaluating experience. Resume's, recommendations, and references are so unreliable and almost always inflated. Work ethic changes over time as well. Virtually all of the decision makers go for the "hard" factors because they are easier to evaluate and they have an impact on rankings.