Just dont think a hat will save you every time, not that hard to break a neck.
No, your hard hat can't save you every time, but it will never hurt to have it on for something worse. Your argument is kinda like saying your steel cap boots won't protect you from broken ankles.
I have broken both head and neck. I was in intensive care for 4 days on the broken head, I walked out of the hospital the next day with 3 broken cervical vertebra. I got the head injury from falling down on a curb while standing up and I got the broken neck from a head-on car crash.
I'm not saying that a broken neck ain't bad, particularly if it damages your spinal chord. I'm not saying that all head injuries are worse than all neck injuries. It's just that your brain is much more fragile to fast blows from hard objects than your neck is. A sharp blow to your skull easily causes a hematoma (subdural or epidural) and before you know it, you just died from getting whacked on the head.
If you can wear a hard hat and laugh off a pine cone hitting you on the head, it's worth wearing it. If you get clubbed by a falling branch and get off with some stitches instead of permanent brain damage, it's all worth it.