VPN is not mutually exclusive with using SSH. What he's saying is that people should firewall their SSH ports to only allow access from trusted IPs, and VPN's make that easier to do.
IE, Why is it important that your SSH port only be connected to by known IPs, but your VPN port is OK to be connected to from anywhere?
You can get in a network by VPN or SSH. Yes, after that you can also log into a computer by SSH, but the question remains - why access the network by VPN instead of SSH?