Starter Kits (Loops) and Starter Packs (Mastodon) have a lot of potential to help improve and surface discovery + following and onboarding.
I know some of you think it should be opt-out, so you can more easily curate lists by adding any account.
But it only takes one malicious user to create a Kit or Pack that can be easily abused by others.
Just one person could ruin the whole feature and its perception across the network, and cause harm.
It's not worth it.
Opt-in prevents abuse.
Period.