I have been guilty of being a copter parent to a certain degree.
Society and how it is now (zero tolerance nonsense) does factor in a bit....everything can be a worry if you let it. It is funny and ironic that adults in society hold children to a higher standard than they hold themselves too with the zero tolerance garbage.
My parenting mistakes were around sports a lot. Having two boys who by nature are very mellow and laid back (and a little lazy) it would frustrate me as I would misunderstand their laid back nature for a lack of caring. Other things I let them take control of early on, like school work. Some mixed results but generally it was ok. As someone else posted I know parents who do their kids work for them, not help them, but do their work for them....these are high school kids. I know others that have gotten "learning disabilities" classification put on their kids work, so, if they fail a test for example they can retest it when there is no need for that. My younger son has some mild dyslexia so his reading has always lagged behind. This of course affects every aspect of school work. He could have had the "retest" condition put on him but I opted against it. A college professor or a boss at a job isn't going to care about it and he won't get "do-overs".
Anyway, since some are going down memory lane, my father told me when I moved out at 17 "I don't expect you to ask for any help." If I wanted to go to college it was on me to pay for it, it was up to me to make my own way. My father is a good man who reasoned no one helped him and it made him tough, so, he wasn't going to help me. Ok, that is one approach. There is a middle ground between that approach and parents micromanaging every aspect of their kids lives.