But I never said you had to spend all your life on passion projects. How is leet code fair game but asking how they would build something they would to even if they never did or do somehow an indication that I think you are a bad engineer? Because I see today's state of system design question interviewing pretty much like leetcode no (asking this as a faang interviewer)?

Having said that what you said about spending 60 hours at work tells others you will be a much better employee. Which is probably the signal they are looking for?