I hike solo most of the time, so I hear that same tired refrain "You'll get killed out there!" etc.
I stop that by saying (and it's the truth) that there has been two kidnappings and one attempted kidnapping from our local mall in the past ten years. We live in a medium-sized town, and that is a pretty high number in my opinion. The last person I said that to just sat there with her mouth open after she realized I was right.
I've never really felt "threatened" on the AT, and if you just go about your business (hiking) then you should be just fine.