IMO the problem is not that you can't block them but tooling. It is true that with the appropriate tools and work you can farm the data yourself and get everyone's votes, but realistically most people aren't going to go out of their way to do that. I see no reason why this would make lemmy better and instead just gives ammunition to bad actors. The poster above you is asking why we need to do more things to avoid bad actors as an effect of the change instead of avoiding that outcome. We know there will be bad actors, but we don't need to make things easy for them. Maybe you were never gonna stop the guy willing to make an instance and look through all your votes, but you'd stop all the ones who wouldn't be willing to put in the effort.