Setting Option+[WIFI ICON MENUBAR CLICK] as default action when clicking the wifi icon in the menu bar
Until now I've only found a workaround:

Install BetterTouchTool and create a special trackpad gesture or mouse gesture to invoke an option+click. In the example below I use the trackpad and a 3 finger double-tap in Global to do that:



From now on a 3 finger double-tap on the Wi-Fi menulet (and other menulets) will reveal the advanced or detailed view.