Eliezer, you seem to be deeply offended by the fact that many people enjoy fantasy over reality, or don’t get a kick out of science. As you put it, they don’t have the scientific attitude that “nothing is mere”.
Yet why should you expect people to be different from the way they are?
You said it yourself: “Part of binding yourself to reality, on an emotional as well as intellectual level, is coming to terms with the fact that you do live here.”
That means accepting the reality that people like the things they like, not wishing for a fantasy world where people magically like the things you think they ought to.
First, can you clarify what you mean by “everything is permissible and nothing is forbidden”?
In my familiar world, “permissible” and “forbidden” refer to certain expected consequences. I can still choose to murder, or cheat, blaspheme, neglect to earn a living, etc; they’re only forbidden in the sense of not wanting to experience the consequences.
Are you suggesting I imagine that the consequences would be different or nonexistent? Or that I would no longer have a preference about consequences? Or something else?