Except that Butler, Foucault, etc. (and those who 'apply' their frameworks to this or that) are not happy simply calling their products 'art,' not even a hermeneutic 'ethics.' Most of them have made, at one point or another, _explicit claims_ to the political, often offering their writings as more 'radical' than Marx (whom Foucault, for instance, classed among other 19th c. political economists). In other words, postmodernists have mainly themselves to blame if their writings have invited what Frances calls consequentialist evaluations of their writings.
That said, most of marxists' and other leftists' on-line rantings + ravings against pomos are silly time-wasters as well. They get dizzy fuming against pomos as if pomos and pomos alone were standing between the status quo and a new upsurge of mass movements, if not the glorious Socialist Revolution itself!
Here we are, in the late, late 20th century, and we got a mini-left-publishing boom (written by a variety of leftists) that have already churned out an ungodly number of articles and books dedicated to 'debunking' pomo. Some of them are useful, but most of them are fillers that do not quite cover many gaps in our revolutionary teeth.
Yoshie