The repetition obviously applies for your search engine that displays solely favicons, but I don't think that there are many duplicate search results.
As you will immediately notice FB, Twitter, Whitehouse.gov, barackobama.com are repeated 3-4 times each, and this is only the 1st 30 results you could continue scrolling down infinitely and you are bound to see the repeat again and again.
My point was user feedback complained of repeated results on my search engine. Users generally thought my results were lower quality than Bing/Google despite being identical depending on the API I was using. Further, I believe a lot of this has to do with Google/Bing users being unable to see a large number of results on the 1st page.
But even linking to different subpages I think Google would prefer users not see multiple FB, Wikipedia, ect... results and that is just one rationale I offer for Google having an interest in limiting results/page (the question of the original submission).