Apart from censorship making nostr more boring when we can't see half the comments.
I can see ways for this to be misused with bots.
Anyone can set up a bunch of reply bots that reply to new users and get followered by those new users.
That's literally how I found people to follow on here in the beginning, I was following the nostr CEO bot and checking it's replies to find new people.
It doesn't actually matter because it's only amethyst, but if a popular client for new comers did this, someone could really mess with people by exploiting it