I guess it's been a while since we've kicked around the "case of the hitchhiker" on THR....
As a dumb kid, I hitch hiked quite a bit.... and on at least one occasion, after getting sick and being abandoned by my "buddies" ~20 miles from home, on the wrong side of town, I was greatly helped by a man who obviously drove out of his way to deposit me near my home.
On one Sunday evening in CT, a navy buddy was driving back to the base with me from RI and we stopped to help a station wagon with a flat tire, which was occupied by a mother, a sickly looking grand father and a gaggle of kids . As soon as we stopped to offer assistance this other guy, in a pick-up truck, who had stopped before us, very quickly got in his vehicle and took off. The mother was apparently the only one who spoke any English, went on to tell us that the guy who took off had offered help, but insisted that the pretty ~12 year old girl go with him alone, to get the tire repaired.
Much to my amazement, we found a gas station where the woman was able to buy a second hand tire and get it mounted, and saw them on their way.
We all have to decide how we are going to live our lives and what risks we will take. For some of us, the possibility of doing a good turn unto others is worth the risk.
Now that I have a family that depends on my support, I'm much more reticent about hitchhikers. But I don't have a never or always rule. I take each case one at a time..... considering things such as how many (if you've got a buddy to walk with, you'll likely get to enjoy your walk), size (can I take him), time of day, what I've got going on, etc....
If I'm on my way to work and I see a guy at 7:30 a.m., with a lunch box in his hand, wearing a mechanics uniform, on a well traveled road, he's probably going to get a lift, as will the teenager with the book bag.
I can't say that I've ever given a girl hitchhiker a lift, as I can't ever recall seeing one.
Times have changed and extra caution is certainly warranted.
I think the O.P. needs to invite his wife to read this thread and discuss the events in a constructive way, as she clearly influenced his decision to stop.
Do unto others as you can and as seems prudent. Though dying at the hands of a drunk pot head isn't exactly how I want to go out of this life, there are far worse fates potentially up around the next corner.
Life is not a risk free endeavor.