There are many problems with punishment today.  Why?  Because punishment is not always the answer.  Punishment does not help good behavior.  By punishing a toddler, do you really think that punishing them will enforce their good behavior?  Absolutely not.  Which leads to the child avoiding the punisher because they simply do not care.  Punishment is used thinking it will benefit everyone in the end, but most of the time it does not.  I babysit kids from the ages 1-3.  Especially with the 3 year old, enforcing punishment on him results in him becoming aggressive.