Then don’t ever read gallery announcements for upcoming art shows. But if you love pretentious bullshit, check out the Art Baloney Blog. h/t to Gabriel and Jeff Edelstein for passing it along.
Here’s a favorite (mostly because I like the habits/habitus/habille echos):
“Light polystyrene forms seem to float in space and invite visitors to metaphorically disrobe—to remove their garmentlike outward appearance, their habitus, to assume another way of being, more introverted and intimate, enigmatic and silent.”
(source: Eugenio Viola reviewing Enzo Cucchi @ Museo Nazionale di Capodimonte, artforum.com)
whatisthewhat 
I remember walking past a gallery once where the window displayed both a painting and an artist’s manifesto displayed next to it. In art, as in political rhetoric, if you’re explaining, you’re losing.
Overall, I blame the 20th century shift from art as a craft to more conceptualist approaches.
I’ve actually recently gotten interested (and am trying to interest a student) in a comparison of political and artistic manifestos. Why do you conclude that explaining = losing? Are there modes of explanation that are less correlated with unwanted outcomes, do you think?
i just mean it in the sense that most people aren’t terribly interested in art that has to be explained to them so artists who create works that don’t make any sense without the footnotes are setting themselves up for failure. note that i’m not speaking from expertise but intuition and prejudice.
on the subject of conceptual art approaches, i recommend that you check out Galenson’s “Young Geniuses and Old Masters” book. it even has a bit on manifestoes.
in terms of a political analogy I think you could make a pretty straight forward application of the artistic conceptualist/experimentalist dichotomy, with the former including Marxism and anarcho-capitalism against the latter including pragmatism and Burkean conservatism.