I was about 21 years old the first time I shot a gun. I rented a 38 special revolver at a range, fired about 100 rounds through it, and was done. I just needed to see what it was like. What I learned from that session was that a gun needs to be respected. I enjoyed shooting but wasn't ready to have one yet.
Years later I was at a Bass Pro Shops looking at camping stuff, went by the gun counter, and since my FOID card was expired, couldn't even touch a gun. Well I couldn't have that!! After renewing my card, I can honestly say I've become somewhat of a firearms enthusiast. I invite as many people to the range as I can, and am making believers of some of the "newbies".
Like others have said, some people are scared because they don't know enough about shooting and guns in general.