[jypepin]

Yes and No. You want to build your reputation as a good interviewer, but that doesn't only mean you are tough and let only amazing candidates pass. That also means that you are usually aligned with the interview committee, and if you constantly are a NO when 90% of the committee is a YES and the candidate ends up being hired, then you'll end up building this reputation of being too tough or just not getting the right signals.

I've done 300+ interviews at Uber where the process is somewhat similar to Google, and OP's points are true. As an interviewer all you really want is get good signals either good or bad. And yes, an interview is much nicer when the candidate is doing great.