I generally agree with your overview. I do have some thoughts that I've highlighted below:
The Consensus T14 Law Schools are at:
Yale, Harvard, Stanford, NYU, Columbia, Chicago, Michigan, Berkeley, UVA, UPenn, Duke, Northwestern, Cornell, GULC
That is the consensus of what the T14 is comprised of (i.e. none of these schools were ever ranked outside of the top 14 since US News first began their rankings in the 80s). While it's likely that this poster is aware of this, the US News rankings are not the end-all for law schools. Within the T14, you should be looking at specific programs that are offered by each school. There are, however, subgroups that divide the T14 into tiers (i.e. HYS -> CCN -> MVP -> BDNCG; the orders within each subgroup, and sometimes cross-groups, are completely interchangeable depending on what type of law/career the person wants to pursue). Outside of the T14, it might make more sense for someone to attend a lower ranked regional law school that dominates the market they want to work and is willing to offer the applicant more scholarship money. It all depends on what you want to do with a law degree.
Apologies if this sounds like a humble-brag but to illustrate how little rankings matter once you get within the T14... I'm currently facing the decision of choosing between Mich, Penn and Northwestern and it is an extremely difficult choice. Northwestern has the most b-school lean out of any law school and 95%+ of its students have had at least one year of full-time post-UG work experience--which is extremely attractive to me. UPenn has Wharton and allows a plethora of degrees and certifications between its different graduate programs. UPenn also has the "international prestige" of being an ivy league school which, even though it's just an athletic conference within the US, internationally seems to carry a lot more weight; having access to every other ivy league schools' library database isn't a bad thing either. And while Northwestern and UPenn both have extremely renowned professors, UMich is known for their absolutely amazing professors who put priority in teaching as opposed to being focused solely on research e.g. J.J. White, who literally wrote the book on commercial law and transactions (Uniform Commercial Code), is also an absolutely fantastic professor inside the classroom. UMich also has a much more balanced small-town midwestern atmosphere which is pretty attractive to me.As a Virginian, I can tell you for sure that UVA law is essentially a private school, because it doesn't take state funding which is instead drawn to the undergrad program. UVA-Darden is also like the law school in this regard. Michigan and Berkeley are prob like this too given that the law schools are nationally elite.
It's mostly true that UVA is more similar to a private than a public but there is still a big distinction. Both UVA and University of Texas (ranked 14 this year but typically not regarded as a T14 school because 2011 was the first year UT was ranked within the top 14) have state constitutional quotas for in-state students. These quotas are no joke. UVA's student body MUST contain 40% Virginia residents and UT's student body MUST contain 65% Texas residents. Obviously this is a huge advantage for residents of those states. Private schools have no such quotas. While UMich is a public school and the dean of admissions has said that she wants to actively recruit more Michigan residents, there are no quotas in Michigan and the data suggests that their students come from all around the US/world.A JD/MBA or MBA/JD depending on how you want to think about it looks like a pretty damn good deal considering that every law school here has a good business school too, though some business schools' reputations aren't quite as hot as the law schools (Georgetown, Yale only because the Law School is so elite) and vice versa with UPenn being the biggest culprit here because of Wharton's reputation.
I would say that law schools are very numbers driven because of these factors:
1. There are only 200 law schools in the US and nearly the entire LSAT pool (minus the Canadian Law applicants) apply to these 200 schools. The entire GMAT test takers' pool spans a lot more schools and therefore, the super high GPA guys are spread out more internationally at least among Americans.
2. Most law schools enroll students right out of college and students who are typically no older than 25 (two or three years out of college). Students entering in their late 20's are likely the bridge between the young'uns right out of college and the outlier older folks. Note that Northwestern is an exception to this but it doesn't seem to be this way at most schools.
3. Law is a totally new profession for everyone who gets in law school. Even if you were a paralegal or legal secretary before school, you will prob still have to change your way of thinking in class, at least from my friends who went to law school, and there were plenty.
I think there are many different reasons why law school admissions are a numbers driven game. The points you've stated may very well all play a role in their decision making process. (Personally, I think #2 plays the biggest role out of the three.) But directly from a couple of the deans at T14s' mouths... it's because of US News Rankings. So many applicants use those rankings to decide where they want to go to school and the most direct way a potential student can affect a law school's ranking is by your UGPA and LSAT--making up 22.5% of a school's ranking. If you're interested in their methodology you can see it here. The deans I spoke with all said that if applicants didn't use US News as much as they did, the law schools wouldn't have to cater to the rankings either. However, THAT'S the way things currently are and anyone who's seriously interested in law school should work hard to bring up your GPA, if still finishing up your undergrad, and make sure to study hard and not take the LSAT lightly.Please feel free to correct me if I'm totally wrong