We don't spank our kids but there are times I really want to.
Kids are impulsive, no matter what you tell them, how many times you talk with them about proper behavior and how to solve problems without shoving, kicking, hitting, pinching, throwing things at their younger siblings, because they wanted to play with your purple pony instead of the red, blue, yellow or white pony. Or she'll get in her mind to horse around and run around the house until she runs into a doorknob or something which will result in the umpteenth discussion about: "why did you do that? I told you you're going to hurt yourself" while she cries her lungs out.
The older they get, the more potential for mayhem. Wait till they can drive a car...I shudder at the thought.
You can't control your kids 100% of the time (after they learn how to walk), unless you put them in a straightjacket (yes, thought of that once or twice). They will hurt themselves, they will hurt others, they will probably hurt you, they will misbehave, they will drive you crazy. And when they do, only saints don't think about doing crazy things.
Young children do NOT have a survival instinct. The smarter ones will develop one after they hurt themselves a few times.
Because stuff gets broken. My 2 year old daughter has worked out that while lying on the floor screaming generally doesn't get you too much attention, trying to throw an expensive vase or the TV on the floor will.
Also I like curling up in the sofa after my daughter has gone to bed and watching a good movie far too much to consider getting rid of the TV.
If singing in the car is even registers as misbehaving or disobedient on your scale then I think you should count yourself incredibly lucky that you have very well behaved child.