That sort of stuff is really only necessary if on your home network you're doing port passthroughs or if this machine is directly connected to the internet with a public IP. For most users behind a router, you don't really need fail2ban and iptables.

Caveat: I haven't read the article linked in the GP, yet. (I will.) But the comments here immediately elicit this thought:

How many users have a laptop that they are connecting to one or another undefined (to them) form of "public" wifi? (And/or to someone else's internal network that may be compromised.)

Even then, out of the box, the only services listening to ports are dhcp and mdns.