I'm pretty sure they're incentivized to find candidates that get offers - not to find "good employees" or anything of that sort.

I would think there is a Venn diagram with an overlapping 'sweet spot': Good employees are probably more likely to get offers, as are candidates that prepare for an interview.

Similar experience, spent the same time preparing for the interview as for any other company + couple of hours of browsing some slides from university classes on data structures (sorry Google, you are not a special snowflake) - rejected after the first call:)

  It's a little unbelievable.

If they believe they have the _ideal_ benchmark for a good employee, anything you do that improves your score makes you a better employee.