I think there are certainly times where there is a negative consequence, and you should rationally say no. I disagree that it is always trivially easy to recogn

I think there are certainly times where there is a negative consequence, and you should rationally say no. I disagree that it is always trivially easy to recognize and classify the situation, and for most parents, being unsure translates to No. Parent poster is encouraging people to do the work in those situations and decide whether there really is a negative consequence that isn't worth bearing, and encouraging them to raise their level of unacceptable risk. I think you're engaging in black and white thinking by saying things are either dangerous or not. There's an in between.