My guess is that the increased ability of technology to identify low-hanging fruit is stronger than the increased use of indexing's decrease in focus on finding "mispriced" assets. If there's money to be made, someone will find it. Even with indexing, there are still people who dream of beating the market and try new approaches to do that.
Web-based stock-trading technology has been around for 20 years, and the fundamental analysis of companies' spreadsheets is remarkably easy and can be coded by anybody. The real trick lies in identifying the moats and margins of safety... That's why there aren't "cyber Buffetts" running giant profitable hedge funds with their supercomputers. ;)
I wonder what percent of these disciplines have read the Buffett Partnership letters.
Very low, I'd wager. A lot of people are only there for the sales and idol worship. Each year, almost half the auditorium clears out after lunch to go shopping instead of listening to the second part of Buffett's Q&A.
As for the article in the OP, there are always opportunities, especially in volatile, unstable, emotionally driven markets like the one we have now. Benjamin Graham had many successful disciples other than Buffett, and each of them adopted the basic Graham strategy to their own purposes. Look up Walter Schloss, for example...