I'm new to Aikido (and posting on this site). I believe the word most are missing is "ever" in the poll question. I said "yes" remembering that with in my first few days of training I was going to throw someone but realized that he was going to land off the mat. I asked to stop and move from the edge so he would be safe to fall. He refused stating that I should determine where I am going to throw Uke and to make sure I don't throw him off the edge of the mat. Was I afraid of unintentionally hurting him? You bet!! (I was able to keep him on the mat after all—lesson learned).
I remember lacking trust that my Uke would do his/her best to stay safe in spite of my poor execution of a technique. (New folks always get a Sr. Student for Uke in our dojo). Hence, there were times I was afraid of hurting Uke just do to my inexperience/lack of confidence. (Still have both problems but now I trust my Uke to stay safe, keep me safe and correct me immediately when I am not.)
Every one was new to Aikido at one time or another ..... "ever" been afraid of hurting Uke unintentionally? Not still afraid, not continuing to be afraid…. I can't imagine anyone being able to answer "no" they have never been afraid.
My 2 cents from a new beginner's perspective.