> As for the part that is just wrong, there’s never been an internet where you had to know the connection address (there were periodically updated host files)
Not necessarily. If your Internet connection was via KA9Q NOS over a DOS packet driver running SLFP (the predecessor to SLIP), you had to keep your own hosts file, and people would trade things like Scott Yannoff's list. If you look at http://www.nic.funet.fi/index/gnu/funet/historical-funet-gnu... for example, they'd list IP addresses and ports because some users didn't have systems connected to DNS.
People aren't talking about Telnet(23/tcp) as a protocol, they use that terminology because the command-line unix "telnet" client when connecting to a non-Telnet-service (meaning doesn't exchange WILL/WONT handshakes etc) on another port, it effectively acted like netcat. So if there was a cool game listening on 10.123.45.6 port 2000, people would type "telnet 10.123.45.6 2000" to connect to the game from many places.