Why do conservatives call GOP members RINO's, but then praise those same people?

First it was "Newt Gingrich the RINO was behind the Clinton era surplus", now Alan Greenspan is a "Keynesian in GOP Clothing" whose massive stimulus spending was working until Clinton came along and ruined it. Is the point of this sort of thing basically to say that "real" Republicans don't know what they are doing? If so, maybe we're all more in agreement than anybody previously realized.