Mainly that everything is publicly routable. People see a 10.x and instantly know it can't be reached from the public internet. IPv6 is much harder. For inte

Mainly that everything is publicly routable. People see a 10.x and instantly know it can't be reached from the public internet. IPv6 is much harder. For internal-only stuff there is the fd00::/8 block, which AWS actually does use, but there is no equivalent range for outgoing-only connections.