Cinnamonsun, I think it’s more important to maintain healthy boundaries than appease or accommodate others by accepting friend requests that you’re not entirely comfortable with. If they’re not ok with that, they’re not the right person for you, end of.
I recently went back on Facebook, too, not to find new friends but I did get one request, which I rejected as I didn’t know him, and like you, I questioned his motives - like why he would reach out to a random woman (me) who hasn’t even uploaded a photo of themselves.