I considered the common frequency and yes it would certainly work in an ideal world. But there are too many old and bolds who quite simply switch off their radio when flying in class G. On top of that there are those who refuse to have radios and those who are too busy to be for ever changing frequency. Class E above 700feet agl - good idea. As for traffic separation based on the weather turning airfields into graveyards......
I am all for GPS, maybe approaches if they can be protected. But I think it is wrong make private VFR aviation more complicated or expensive. I would love to be able to jump into an aircraft and fly where I want, when I want and talk to who I want. That is the essence of aviation - freedom.