Troughout the history many things that were new and strange seemed dangerous or scary.
In the past, people thought that it would be dangerous to move fast with a train, that our body would break or something like that.
People were scared of electricity and didn't trust this "magic".
Or you know, there are still older person who don't understand the internet and don't stay away from it.
The concept of life after death is strange for most people. Over thousands of years belief systems have been formed around this topic and many of them incorporate fear(hell, karma, a big judgement, black darkness etc.)
It only seems scary, because we aren't used to this thought and this is completely natural, but the collective fear of death will reduce in the next few decades, when everybody will know and experience his connection to "the other side"
