I really hope that a tragedy doesn't happen before devs start realizing that community safety is more important than growth.
Cool. Stuff goes viral on the Fediverse.
But you know what's more cool? If stuff goes viral and neo-Nazis don't see that as an opportunity to spread their filth.
And no, blocking shouldn't be the only option -- Neo-Nazis are very adept at switching instances if their instances get shut out.