Kinda lame and not in line with what made PageRank so successful. Google should "not be evil" and have the decency to be as neutral as possible, allowing legitimate clicks and backlinks to judge the relevance of a website. If people can't stand websites that aren't tailored to mobile devices, they will simply leave and find another. I personally don't mind viewing a 20-year-old website through a little mobile browser if the content is satisfactory.
If they are to change anything in this area, they should simply put a little distinguishing checkmark by a mobile-friendly search result, but leave the rankings unchanged. And this should obviously be the case only when a user is on a mobile device.