You seem to be confusing applicants with people who are given interviews
No, I'm not. From shminux's link:
The "Fizz-Buzz test" is an interview question designed to help filter out the 99.5% of programming job candidates who can't seem to program their way out of a wet paper bag
The quote does not claim there has been no filtering done before the interview stage. If you read the original source it explicitly states that it is considering all aplicants, not only those who make it to the interview stage: "We get between 100 and 200 [resumes] per opening."
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.