It's part of the overall moderation and abuse issues.
It's not that hard to figure out how to give users control over if they are included in starter packs or not. BlueSky hasn't done this yet, but should.
It's not that hard to moderate accounts that make starter packs for the purpose of abusing other users.
But even still, there are like 15 more important abuse vectors that need to be closed down before I worry about starter packs.