Would you please show from posts by non Catholics that they have stated that belief please. As a courtesy to you I’ll save this question so I don’t miss your answer. Surely you wouldn’t make such a scurrilous claim if you couldn’t show definitively where someone made that claim.
What do you think that Once Saved Always Saved means? What do you think comes from the belief that one cannot lose one’s salvation no matter what he does? You have seen as much as I have here and elsewhere from individuals who essentially feel free to do what they want whenever they want to, to the extent that they want to, simply because they believe themselves saved.