I'm trying to figure out the statement that WiFi is not a security feature?  It's also not an easier way to connect wirelessly, It is the way to connect wirelessly.  WiFi is a communications protocol, nothing more, nothing less.  The securities features are just a part of the protocol, and come in many forms.  Using the PIN and the push button are just different ways of setting up the security.  I personally prefer to do it manually, it's just as easy (possibly easier) and you're sure of what's happening.  Sounds like the person at D-Link was also confused on this subject.