btw im not entirely sure why people here seem to think that tznius and l’shem shamayim are mutually exclusive these days…as was pointed out by several users, the standards of tznius in recent years have gone up. i have seen pictures of my grandmother where she wore dresses that didnt cover or cume up to her elbow, but now she wouldnt dream of it. why? because our adherence to tznius has become more stringent. (by our adherence i mean NYC and its environs…i cant speak for out of town)
another thing that our parents and grandparents were more lax on was music. there wasnt much jewish music back then so many if not most listened to whatever non-jewish music they could get their hands on. many of those people wouldnt dream of listening to anything that isnt sold by mostly music today. the standards have changed, is that not l’shem shamayim? today if a school finds a kid with a non-jewish music laden iPod or the like the kid is given detention, the iPod is confiscated and the parents may be called, is that because we’re simply outwardly being more frum while we really are no different from our parents and grandparents? i dont think so. they made us what we are today with all our chumros and hiddurim, it wasnt our invention, i think we can safely say that it was l’shem shamayim.
what about going to dances? i know that was common back in the day, now if it happened a kid would be thrown out of school faster than you could say “off the derech” does that mean that our standards of gender separation have gotten higher because of some bias against women? or was that always halacha and previous generations were lax, for whatever reason, and our new standards are l’shem shamayim? ill go with the latter.
my parents and grandparents used to be a little more lax with kashrus as children. ask your parents and grandparents if they chewed gum that didnt have a hechsher, or ate good and plenty even though it had no hechsher, i think you’ll find that they did. it was very common back then. it wouldnt happen today, and if a kid in school was caught doing it he would get yelled at by his menahel. is that wrong? are our standards in kashrus higher because we’re really less frum? does that make sense? no i’d say its l’shem shamayim.
im not judging previous generations, im sure that our children and grandchildren will have the same conversation as us. but to get stuck in the past and have the attitude that “we did it, if it was good enough for us its good enough for you” is completely ridiculous. what our parents and grandparents did obviously turned us into the people we are today, with all our chumros, and im sure they are and would be proud of us.
as for why a school would refuse to accept a child whose parents are lax on certain issues? firstly because the hashkafah may be wrong in the house of the parents are aware of communal and societal norms and despite that buck them and those hashkafos may rub off on other kids this kid befriends. secondly everyone knows that the responsibility of a yeshiva extends past the walls of the yeshiva to the entire spiritual wellbeing of every student. kids have friends over, and the yeshiva has no interest in that friend being negatively influenced, or introduced to things he may not otherwise have been aware of.
so the argument can be made that accepting this kid will influence him positively and that will diffuse to the parents and the whole family will grow as a result of the yeshiva accepting this kid, but realistically which is more likely: a kid influencing his family positively, or a kid influencing another student negatively? i would say the latter.
this is all for NYC or any major jewish community where there is a dearth of yeshivos from which to choose; there is always a yeshiva for everyone. in out of town communities this is obviously a much tougher decision for school administrators.
one thing i will say though (in addition to the many things i said above), is that if a kid isnt accepted my mainstream yeshivos then there are other places for him to go be it a kiruv yeshiva or maybe a more modern orthodox yeshiva or maybe a mix of both depending on the exact situation. however there is a certain stigma to attending such yeshivos and that, many times, backs parents into a corner and, in a way, forces them to got their kid into a mainstream yeshiva or else. i know many guys who should never have been in a regular yeshiva but were anyway because to their parents the idea of them attending anything but was untenable and they came off worse for it. i also know guys whose parents and rebbeim realized early on that mainstream yeshiva was not for him and switched him to another, more off the beaten track yeshiva and today hes doing just fine. its possible that its coincidence, but i dont think so.