There are ranges of 'ill-equipped' and ranges of danger. I think also the attitude of the person doing the warning has an effect.

I think that pointing out some potential problems for consideration is helpful, but I'm not a cop, I don't wear a badge and carry a gun, and I can't arrest people for being either inexperienced or stupid. I see no reason to insult someone who is inexperienced, as I see done frequently by self-called experts.

As you say, we've all done stupid things and lived, so my expectation is that most people will live after making mistakes. But offending the inexperienced with a superior, insulting manner makes warnings difficult to take.

When I offer advice, I'm always prepared to have it rejected without being offended. It's not my life and limb at risk, and I'm happy to let others make their own mistakes. That's how I learned.

Of course, I'm generally not on the summit of some god-forsaken mountain nor on the rim of some bottomless chasm, so I'm back to the range of danger. Let'em screw up, I say. That's how they get to be the ones to offer advice.