Historically, nu-light is revealed in response to a legal or financial need...
I remember when that 5/1975 KM came out. My "unbelieving husband" and I asked an elder friend of ours what it was all about and he told us only Ordained Ministers could seek "ministerial deductions" on their income tax, and get reduced rates on airline tickets, theme park admissions, etc.
The more he talked, the more shocked we were, because we had no idea that he (and, by extension, his wife) were getting all these perks!
My guess is that the IRS, the airlines, the theme parks, restaurants, etc. were getting tired of losing money on said "ordained ministers" and envisioned a time when just about anyone could print up an ID card and get a price break. A few phone calls and a bit of correspondence later and, voila!, nu-light!