How exactly are Confucious or Gautama "paragons of Western culture"? As a Westerner myself, Western works are more familiar to me, thus my chosen list of examples is obviously deficient.
Are you totally unaware of the artistry and the influence of the Upanashids? The I Ching? The Tao Te Ching? The Art of War? The Annalects of Confucious? The Book of Five Rings? The Tale of Genji? All of these are equal to anything in the Western Canon. The loss of any one of them would diminish all human culture, not merely that of India or China or Japan. I am not a scholar in any sense, not even casually, of Indian or Chinese history, but I am familiar with the above titles simply from perusing the bookshelves of any decent sized English language bookstore.
What is more, the effect of the loss of this material upon the modern cultures of the nations that arose where the Aztec and Maya once reigned can not be fully guaged. It is conceivable that with a deeper, more fully realized indigenous cultural tradition, modern Mexico, Guatemala, and Honduras would not be as dysfunctional as they are today, that continuity of tradition would have allowed for a smoother, less traumatic path of development. Further, the loss to succeeding generations of artists - whether Mexican, Guatemaltecan, or international - will never be known. Perhaps De Bello Civili is only of interest to "scholars of history", but its loss would likely have denied the rest of us a little piece of Shakespeare's genius.
As for the Malay, my ignorance of what genius may or may not lie within their literature is utterly irrelevant to what in all probability was lost with the eradication of the sum total of Mesomarican literary tradition. The destruction of the Aztec and Maya libraries does not equate to the loss of Malay or English writings. It is the equivalent of the loss of everything ever written Latin and Greek - an entire civilization's accomplishments, not merely one country's.
Finally, mathematics and astronomy are both the result of a long, slow accumulation of knowledge. Modern mathematics, and all that modern civilization has built upon mathematics, would not be any where nearly as advanced if one were to strip away the contributions of only one of the Greeks, the Arabs, or the Indians. Whether even a single non-specialist ever studied Maya science has zero bearing on what a later genius such as a Newton or an Einstein could have done to advance all of human civilization with the knowledge denied to us by the Spanish authorities. And this does not even take into consideration the death of a living, breathing tradition of intellectual inquiry that might have led to god-knows-what - earlier space flight, the cure for cancer, cold fusion, a longer lasting light bulb.
