If whipping someone into following the Torah would work (and the goyish authorities wouldn’t intervene), then we should utilize that method. In fact, beis din did exactly that when the goyim didn’t stop us.
this seems to me a very shallow conversation. even if these people do not become frum at least they experienced an iota of Jewishness in their life! maybe this is the 1 thing that they will experienced their whole life?? and who knows if their pintele nishama will be sparked or not??
Even if not a single person becomes frum, even if they don’t keep the entire single Shabbos, some of them will have kept Shabbos for a few hours, not driven, heard some brochos, said amen, maybe went to shul, heard some divrei Torah, so they surely got a few mitzvos for coming for that Shabbos and it was well worth it.