Most big companies I applied at had about half of the grilling and the rest of the interview was "culture fit"
Running a company is a team activity. I think there are too many sports metaphors in business, but if you've ever played a team sport you realize that the best teams are usually the ones with the players who play best together, not the ones with the most talented players. I could run this metaphor in to the ground, but the point is that hiring only the "best-of-the-best" is neither a credible claim nor a good methodology for creating a successful business. You might be able to do that when your company is 5 people, but it's probably much better to have good role players who are a cultural fit for your organization in the long run.