While this is true, if widely implemented it would mean that legitimate new users will NEVER break into anyone's web of trust, unless they already know someone on Nostr who immediately follows them. Every new user would need an existing user as a kind of "sponsor" to get started. That may be feasible when Nostr is more well-known and virtually everyone knows SOMEONE who's already on it, but that's going to be a while.

For now, I think we need to find another method of combating spam than full web of trust lock-down, especially since it doesn't address the issue of the spam still taking up space on the relays.