The fact that there are different canons doesn't change the fact that the #1 place all judges start (and end) is now the text. In the 1970s, the text was not analyzed at all. Scalia is the person who changed that. None of what I just said is really disputable and is, in fact, widely acknowledged by legal liberals and conservatives.
The fact that Judge Posner disagrees is also completely beside the point.
You are overstating the lack of textual analysis prior to Scalia coming on the scene, and as a result overstating his influence. As a law student who has read a shytload of cases from the 1970's to make the statement that "the text was not analyzed at all" is heavy handed to say the very least. Textualism posits primarily that the text should be given the most weight and most importantly that legislative history should not be taken into consideration. Furthermore, taking into consideration political and social impact was trivial if not outright irrelevant to Scalia in regards to interpretation, unless it was something he strongly believed in like in Heller in which case he cherry picked antiquated sources to further his argument.
Most judges don't simply dismiss legislative history, or dismiss real life impact. Although Scalia has more general notoriety, I personally consider Judge Easterbrook to be a better defender and more interesting scholar in relation to textualism.