Yes you are correct, the current school of thought is as you suggest - but the advice is aimed at individuals rather than a shared password like WIFI.
In a commercial environment, you may have a turn over of privileged IT staff who had access to the passwords, therefore they are likely to need to be changed regularly in line with staff movements.
Setting up hidden SSID’s (along with the necessary firewall rules) and the like is good advice however this also assumes a level of technical understanding which may not always be present - and hacking generally occurs through the simplest methods and gateways.