To use your work example - if you were having trouble meeting a deadline, would you want your boss to sit down with you, hear you out, listen to your explanation and help you find a solution? Or would you be happier if your boss refused to listen to a word you had to say, and only yelled and reprimanded you, threatening to fire you?
It isn't your supervisors job to make you happy, it is your job to make your supervisor happy with your work quality so you can get a paycheck. I don't like comparing kids to adults though, they are developmentally very different and still require a parent, which is why they don't just go out into the world and get a job after they learn to speak and walk. I think in a work situation where a boss knows you almost as well as your mother and knows you were screwing around instead of doing your work, and have been frequently, you would be very lucky to get off with being scolded and threatened with a consequence.
I don't think the pp is suggesting yelling and threats though, it sounds like she is suggesting a consequence for a behavior a mother finds problematic. Gentle discipline doesn't mean no discipline and no consequences. I also think that suggesting that enforcing consequences is going to lead to a child becoming a serial killer is a ridiculous statement to make and it certainly didn't sound like a jokey over-exaggeration. Just because your kids don't have bedtime doesn't mean the kids who do are in a horrible home where demeaning things happen to them.
My dd is only ten and bedtime has always been bedtime so I don't know that I have much to offer. I give my dd a kiss and hug then say goodnight. Sometimes she does have something quick to tell me and I let her, but when she has several stalling things I tell her it is time for bed and that I can't wait for her to tell me more in the morning. On a few occasions I have had to say that it is late and time for bed in a firm voice but that is about it because bedtime has always been bedtime. She has many opportunities throughout the day to tell me things but if I felt that she was truly trying to tell me things she couldn't tell me during the day I would make more of an effort to be available for conversations and one on one time.