I get the sense that you and 'fny are talking past each other. You both have some strong points, and you both have some weak points.

- If a smart student has strong learning strategies, high school classes as a general rule should not be difficult to get good grades in. There are exceptions for demonstrably capricious teachers --these teachers should definitely be avoided and are generally not difficult to identify except in one's first year of high school (even then...). If a student struggles in a class or in a certain discipline (e.g., math or foreign languages) in high school, then I humbly suggest that they are either not that smart, have significant gaps in their learning strategies, or have some sort of learning block. IMHO, all of these things if they persist throughout high school are potentially valid reasons to reject a person from an elite university since they will cause much bigger problems later.

- Contrary to what 'fny says, you can actually get quite a few Bs in high school and still get accepted to an elite school. Ditto with an SAT score that is not close to 1600. The catch is that the applicant needs to make up for it elsewhere in the application. Really interesting candidates don't have problem with this.

- If you think studying Greek and Latin tenses for 20 hours a week is the key to getting a high SAT verbal score, then I think you have been grossly misled. For smart kids, just regularly reading and understanding "high brow" magazines like The Atlantic Monthly, The Economist, Foreign Affairs, The Weekly Standard, The New Yorker, etc. is more than enough to build a very healthy SAT-ready vocabulary as well as high level reading comprehension skills. If you mention the idea of Greek and Latin roots to smart kids, they will be able to figure out what a lot of the core ones are based on their reading. Note that this type of reading will also give them good schemata for higher level writing.

- The "it's for your own good" comment definitely seems arrogant, and it kind of is. That said, it's kind of right, too. It's rough to see a smart kid struggle at an elite school because they lack some fundamentals that a lot of the entering class comes in with (e.g., study strategies, writing skills, background knowledge, etc.). That said, the ones who can "drink from the firehouse" despite mediocre grades are usually obvious to admissions committees since they excel to a phenomenal level on some other vector (e.g., international science fair winner, amazing inventor, etc.).

- You are half right with your comment on risk aversion and taking a risk on a B-student. Without any other evidence that this hypothetical B-student will fit in and/or excel, they are likely to be unhappy as well as be a minor or negative contributor to their peer groups (i.e., they will have to be "carried" in group work and/or they will set the team back by not being able to do adequate work). One of the things that makes elite schools amazing (as well as some honors programs at 2nd tier schools) is that you can learn a lot from your peers.

- Note that I think 'fny is largely talking about the standards for Caucasian and Asian non-athlete non-diversity applicants from the NE corridor and the west coast. There are a metric shit ton of B-students (and worse!) at elite schools. They tend to be recruited athletes (esp. in football and basketball, but in other sports as well), diversity candidates (note that this is not just racial diversity, but also geographical diversity), z-listers, or people coming in with a lot of social capital. There are also vastly different standards for applicants at universities like Penn where they apply to a school within the university. For example, the average profiles for Wharton students and Nursing students are quite different, and this difference can sometimes be magnified by other factors like geographical preference (e.g., a nursing student from rural PA might have an application that would shock a few HNers).

This is a pet topic of mine. If you have any more questions, I will be happy to answer.