As far as children and the general public are concerned, sometimes parents can't win.
For example: my 3 year old throws a tantrum in the middle of the supermarket, I try my best to deal with the situation, but receive all sorts of comments from passers-by. I get tutted at and told things like "my children wouldn't dare behave like that in public", "it's the parents fault" (what 3 year old in the world hasn't done something like that at least once?) "Oh, that's terrible" etc etc. I am mortified by this behaviour, but sometimes little kids get themselves so worked up that you cannot reason with them, and have to take them home. Next time DD throws a tantrum in public I recall the previous incident and resolve to be firm. So while I am sternly telling her off, and she is loudly sobbing (purely for effect), I receive comments like "Oh, she's only young" "there's no need for that", and "the poor girl". Let me stress I am NOT swearing, shouting or being cruel, I am merely looking DD straight in the eyes and telling her sternly that "you WILL NOT kick Mummy again, you WILL NOT roll about the floor", followed by "If you DO NOT stop this NOW, then you will be going straight home to sit on the Naughty Step. Do you understand?" DD acts like I have threatened her with dismemberment and screams louder!
On one occasion DD let go of my hand and tried to run across a busy road. I managed to grab her in time and reprimanded her sharply. (I was shaking, she could have been killed) , only for DD to then to be told by a passing teenaged school boy "tell your mum to shut up". I glared at him and said "Do you expect me to say nothing when she could have been killed?" The reply was "If you were my mum I wouldn't do what you told me either". I then asked the schoolboy what he would do if it was his child, allow him/her to do as they pleased in a dangerous situation? To which he laughed and sauntered off.
Many people I know with kids receive the same treatment, and none of it's helpful.
The exception being a couple of older ladies and on one occasion an elderly gentleman (who must have all had grandchildren like DD) who have been very kind and helpful and coaxed DD out of her tantrum, laughed it off and told me not to worry, that EVERY child behaves like that sometimes. And you also get the odd person who compliments DD when she is well behaved and say things like "Aren't you a clever big girl for mummy".
Sorry for the rant!