Wolf... no one is going to buy into your notion of an egalitarian golden age of the future... especially when you need to skew the facts (lie?) to prove your point:
For example, CCNY (a public university in New York City with open admissions known as the "poor man's Harvard") has produced more Nobel Prize winners then most of the Ivy League universities on the East Coast combined. (No doubt, the Ivy League universities are much injured by their "Legacy" program.)
CCNY has nine Nobel Laureates. Colombia has 96. The University of Chicago has 87. MIT has 77. Harvard has 46. etc...
Anyway, the golden era in literature is not in the past, it is in the future. The other night I discovered there are some very talented, very creative individuals on this very website who are writing innovative work better than some of the stuff in the Norton Anthology of Literature.
And you continue to undermine your argument by suggesting a glaring lapse in critical judgment.
If the Norton Anthology represents the best literary work in the history of man then we have scarcely evolved from the butt-scratching apes in the zoo.
Art evolves in the sense that it changes. Artists must deal with the world in which they exist. But art is not like science. In spite of all our advantages in terms of knowledge and access to the whole of literary history we are not blessed with a wealth of writers today who are inherently greater than Homer, Dante, and Shakespeare.
I have my suspicions that some of the best literary work of the past did not find its way into the canon, but found its way into the garbage can. Manuscripts that contained too much politics, contained unconventional or unpopular ideas, too much sex, too much homosexuality, or simply a writer didn't have the right contacts, or didn't come from the right class of people to have the right contacts - you can bet that any number of factors might prevent a great work from getting published, let alone getting into some canon.
You've been reading too much of the politically correct criticism. You make some rather unlikely suppositions assuming that writers/artists of the past would have acted like writers of today in terms of openly questioning their leaders, their faith, etc... At the same time you miss out on the glaring audacity of many of the greatest writers/artists of the past which in no way supports the notion that the canon is chosen in support of the power elite. Shakespeare was quite likely bisexual, may have had an affair with a mulatto, and wrote plays that were clearly amoral: good does not prevail... evil is not ugly, ignorant and ultimately the loser. Shakespeare's rival atop the canon, Dante audaciously reinvents heaven, hell, and everything in between as he sees fit. Surely Milton would have been much more fit as a role model of the time. And then there's Michelangelo with all his nudity and his pent-up (homo-) sexual frustration exploding above our heads in the very heart of the Catholic Church. Your suspicions prove nothing without digging further.
However, this does not mean I wish to throw out the canon. If you find garbage amongst gold you certainly don't throughout the gold as well. Of course, garbage is a strong word. Perhaps mediocre would be a better word to describe some of the works that are in the canon. I am of course talking about the canon of English literature, as I cannot even begin to comment on the literature of other cultures, as my education unfortunately overly emphasized the literary achievements of a rather backward island on the periphery of Europe.
As others have asked, I would like to know just which works you imagine are "mediocre" and why.