While it is no doubt small consolation, for many (if not all) of the folks who were WLed, there was probably nothing more you could have done. At some point, it is simply a numbers game. The biggest factor is that entering classes today are nearly comprised of ~200 fewer students than when I attended and easily 100-150 fewer than a decade ago, due to significantly lower attrition. Thus, some people who were appointed -- and graduated -- in my day wouldn't get that same chance today.
There are simply too many superb candidates for the available slots. It's the same problem encountered by those applying to Stanford and Yale and other top schools. Admissions officers have to choose and at this level, the decisions aren't easy. Every parent of a kid appointed/admitted believes his/her kid absolutely deserved it, just as parents of those not admitted believe their kid was equally, if not more, qualified than those admitted. It's a no-win scenario.
While this can be a discouraging time, these terrific young men and women will almost certainly go on to greatness in whatever path they decide to pursue.