Just like it's a 100% result if your plane crashes. But we know that, statistically speaking, airline travel is safe and crashes are pretty rare.
So, of the million of interactions between men and unaccompanied children, how many result in some crazy, unjustified child-molester accusation? I'm guessing it's about the same as the percentage of flights that crash.
I don't believe that a handful of anecdotes, considered in isolation, are a good basis for making decisions.
The benefits of air travel outweigh the risk of dying in air crash and other modes of travel are riskier.
However the benefits to the person helping the child is minuscule compared to the risk of ending up in prison and being added to sex offenders list. It is minuscule even compared to the risk of undergoing a criminal trial.
So what? Seriously, so what? If 10 people died from eating crisps (en-US: chips) a year, would you stop? There are endless edge-case examples I could pull out. You can't possibly know what the real odds are because it isn't news when someone /isn't/ asked to move his airline seat away from two children. The reason it isn't news is because it is by far the more common event!
So: Do you want to risk a 1 in a million chance of someone tsk tsking at you until you explain yourself to help a little lost girl? If your answer is "no" then I think that makes you kind of a bad person, just like those United employees.
You could look at it this way: The only way of increasing the perceived probability that an adult talking to a child is just being nice is to increase the number of times that exact event happens.
Unfortuately I'm pretty sure they're all real reported stories. In one case the man asked to move away from his own children was Boris Johnson, the mayor of London[1], when he was an MP in 2006.
If you are a grown adult male in the USA, you will have experienced this. People believe these stories because it aligns with their own personal experiences.
So while few of us have actually been arrested for talking to a minor, and definitely very few have ever had to deal with the police over this, a large portion of us have felt the accusing stare for daring to interact with a child. We've felt the suspicious eyes of every single mother on us as we jog past a playground. We've seen our colleagues and acquaintances make paranoid, disparaging remarks about strangers around their children.
We're not scared of children because of a few scary stories in a few newspapers - we're scared of children because this happens incredibly often and the scary news stories demonstrate just how far these situations can escalate out of control.
All it takes is for one person getting burned to affect their entire social circle. Every person who's been shouted at for trying to help a kid has probably told everyone they know about the event; at that point, none of them are likely to help.
This is especially notable in the social media heavy environment we're in now. I personally know someone who got shouted at because he led a kid to customer service so their parent could be found; posted the event to Facebook, and now everyone he knows (who read the article) is going to be a little less likely to help.
There's a reason Good Samaritan laws had to be put in place; people have been prosecuted for attempting to help others in good faith, and that led to others not trying. Shitty situation, but that's how it goes.
Just today a man was ordered to move his airline seat away from two young children. Until he proved they were his children.
In another story out today a woman aggressively approached a man and threatened him with arrest for taking his own children to a store.
Another man found a lost child and returned the child to its mother, only to be abused and threatened by the mother.
You see enough of this, eventually you conclude "OK, have it your way".