The Paucity of Political Art: Readers React

My art-and-politics posts (here, here and here) have struck a chord, eliciting an unusual number of hits, e-mails and now, reverberations in the blogosphere. Click today’s thought-provoking post on Artblog.net, in which Franklin Einspruch observes:
Only artists whose talents lie in that arena, and mobilize to full effect given a political topic to chew on (Kathe Kollwitz and Ben Shahn come to mind), ought to comment on current events in their work. Everybody else, by doing likewise, is all but guaranteed to make art that falls below the rest of their output.
Another limitation of politically engaged art was identified by Ricardo Fernández, a Cuban-born architect in Miami, in this BlogBack to CultureGrrl:
The more relevant issue regarding Botero in this instance, it seems to me, is whether he is exhibiting any hypocrisy or intellectual dishonesty by engaging in the selective indignation of a response through painting to Abu Ghraib, while not responding to, say, the beheading of Daniel Pearl (and so many others), the deliberate blowing up by Muslim terrorists of children in Baghdad receiving candy from US soldiers, the bodies falling from the top floors of the WTC, the crashing of the planes on 9/11, etc.
As for political engagement, over the years–as you know–there have been U.S. artists who have dealt with ideology and politics; especially so when the times (and the issues) are fraught with controversy. Leon Golub, in his latter phase, produced virtually nothing but denunciations of military and/or police abuse against political dissidents, depicting the squalor and violence of unnamed but specific situations that were rooted in the experience of places like South Africa and Central America. Tragically for the overall integrity of this body of work, he never dealt with the ongoing abuse of a totalitarian police state like Cuba because of his politics.
In questions of politics, when the art entails explicit denunciation, and it is always–or almost always–in one direction even while much greater crimes deserving of condemnation go unremarked, then the result is propaganda and cant.
Related: Where is the new Guernica? in today’s London Telegraph. Writer Serena Davies elicited this comment from Matthew Slotover, co-founder of Frieze magazine and the eponymous art fair:
You can look at what art gets made in times of economic boom and bust, and there’s a difference. The art does get more political when the art market is not as strong. After the art recession of 1991-92, for instance, the Whitney Biennial of 1993 was known as the PC Biennial because it was so political.
“I think, partly, if you are making beautiful paintings then when they’re selling well that gives them their own kind of logic. But, when they’re not selling well, artists and galleries look to bigger issues.”
So we need the art-market bubble to burst, in order for artists to transmute their personal woes into a global critique? What am I missing?