Well, since the user cannot opt out that option isn't given. People will receive unwanted on-chain zaps and from what I've seen so far even those who think they're Veteran Bitcoiners have already doxed addresses. (see my other comment). There is plenty of nostr users who haven't been around 2,,3 or 4 cycles and the self-doxing will be insane.

We could do it in such a way that receiving and sending in and out of Nostr is harder if that is the problem. So, once in, the money stays rotating between nostr keys in an identifiable way like what zaps do. Then in the end, it leaves via a mixing service for instance. Anyway, lots to work yet.