True but now there's a separate danger with botnets. Now, instead of saying "don't own a Rolex" it's "don't own any silver, because that could be used to make a knife and steal someone else's Rolex."
With botnets like Mirai, innocent networks need to protect themselves not to avoid getting attacked themselves but rather to ensure that they don't participate in an attack against someone else.
For young kids, blocks and just letting kids play and build stuff from whatever they find outside is great.
For older kids, Scratch and Coderz (http://gocoderz.com/) are great.