There is a very specific point of argument here:
Rav Dessler was well known to have said that the correct mehalech is to push everyone hard, so that the best may come out of some. If others suffer (and go OTD), so be it. This mehalech would insist on elite schools, where only the best attend, and only “good” families are allowed in.
The other school of thought is that every Yiddishe neshoma is precious, and it is not worth losing any for the betterment of a few.
Those who want “elite” schools are of the first mehalech (your child may affect my child, even if it will cause your child to go OTD)(at least until they have a child who breaks the mold!). Others (such as Rav Birnbaum from above, Rabbi Bender of Yeshiva Darchei Torah (who deserves special mention for his work with special children), etc.) are of the second mehalech, and try to educate every Yiddishe neshoma.