It is not at all "easy to misconfigure". First of all, the manufacturer is going to configure it for you in 99% of cases, just as they do for IPv4. Second, even

It is not at all "easy to misconfigure". First of all, the manufacturer is going to configure it for you in 99% of cases, just as they do for IPv4. Second, even if you want to roll your own firewall rules, it's trivial to set up a default deny on all incoming traffic.