>> , yihay mechanecha kosdosh … nowhere in the torah does it say we need to reach out to non frum.
This is exactly why Hashem sent Moshe to gather all 36 tzadikim and made them march to EY, rather than bother wiht millions of Amei Haarertz!
There is a fine difference between dealing with Jews who are against and those who are lost. R Salanter moved from Litva to West, saying that you can’t stop the guy going down the slope but you can talk to him at the bottom.
So, while the desire to keep the camp holy is understandable as self-protection, it is definitely a perversion of Torah to say that we don’t care about other Jews. Early advocates of the self-preservation system, like Hazon Ish, surely undertood the trade-offs but it seems that this is leading to kefira after several generations of self-preservationists teaching each other.