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.
"WiFi is a communications protocol, nothing more, nothing less." you said it all.
"The securities features are just a part of the protocol, and come in many forms. " This is where I believe you are mistaken.
WiFi is communications protocal. Security is different.
Make it simple.
The keys to your car is the security, has nothing to do with how it runs, it just enables it to or not run.