Interesting question, it raises the point, why do we have emotions at all?
This isn’t something I know a huge amount about, to be honest. The most obvious explanation to me is that we would have evolved to fear things because it’s probably sensible to want to get away from things which might have eaten us, attacked us, or in some other way been a threat.
But there are also things that we fear that aren’t very likely to hurt us. I suppose that it’s possible that people have bad experiences with certain things when they were young, or perhaps they have a phobia. Fascinating stuff 🙂