What is there poetical about being in revolt?

You might as well say that it is poetical to be sea-sick. Being sick is a revolt. Both being sick and being rebellious may be the wholesome thing on certain desperate occasions; but I'm hanged if I can see why they are poetical. Revolt in the abstract is—revolting. It's mere vomiting.—G.K. Chesterton, The Man Who Was Thursday

In art, love of the law translates into two complimentary forms of piety: the piety of craft married to the piety of subject matter.

The piety of craft: because fundamental to craft is reverence for tradition. The modern devaluation of craft is a profanation.

Sacred time is circular. It is an incessant return to origins. Therefore, sacred art finds invention in the  retelling of the same stories, in the reverential recreation of the same forms. The modern striving for novelty is a profanation.

The desacralization of the sacred object,

Paul McCarthy, Complex Pile, 2007

which took the form of its transformation into art, gave art access to possibilities that could no be realized as long as art remained bound to tradition. The ability to exploit these possibilities appeared, initially, to inject new vigor into art. Untethered from its religious obligations, art became a source of novelties and sensations. 

It took a while for the consequences of this putative liberation to make themselves felt, but by the mid-twentieth century it had become readily apparent that in the pursuit of novelty, art had forged a path to banality. 

Art history has created a false image of continuity between the sacred object and the art object, subsuming both into the profane temporality of linear progression. It has forced them to share a history despite their being entirely different species. Indeed, the sacred object, as a symbol of the absolute and the eternal, only has meaning outside the flux of history. The profane art object is from its inception subject to the vapid exigencies of fashion. 

The emptying out of art, its diminution into mere cipher of exchange value, was for a time covered up by the supposed heroism of an avant-garde at war with outworn academic ideals.  But once the modernist moment was over, it was plain for all to see that the putative liberation of art from tradition was the prelude to its abjection.

Finally, with the advent of the readymade and the objects and attitudes it spawned, art dissolves in and becomes one with its commodity-glutted profane milieu. The appropriation of the banal does not close the gap between "art" and "life" because that gap was opened by modernity, when it replaced the masterful and sacralized production of everyday objects by industrial fabrication and artisans by coerced and alienated laborers. High and low were sundered when the High (the transcendent) was removed from the lives of the low. No purely artistic maneuver could restore that connection. The theatrics of the readymade do not overcome the disjunction of high and low, art and life. They merely reveal the insignificance and superfluity of art when it no longer has a sacred purpose and is reduced to making a spectacle out of its own debasement. 

Early modernists like Mallarmé did not envisage this. Art was supposed to redeem the squalor of modern life. Instead, it became part of it.