Fascinating thread, albeit somewhat circular.
I remember once being shocked on a MN thread by people who wouldn't leave their child "alone" to go and hang out washing in the garden. I am frequently shocked by the brigade who wouldn't leave a child "alone" in a car to pay for petrol, whenever this thorny issue is raised on MN. I have always done both without a thought.
I have also done many things now frowned upon - I put all my babies in their own room at home from about 6/8 weeks for naps and at night. I have added infant formula to cooled water to mix feeds - the advice about hot water needed to kill the bacteria in the formula was unheard of then. I have left them asleep upstairs in a very small hotel, with a baby monitor, while I ate in the restaurant downstairs. I have also left them asleep with a baby listening service at a Mark Warner hotel whilst I ate in the restaurant, which everyone did on Mark Warner holidays, pre Madeleine. Later, on annual camping holidays my children have had a lot of freedom to roam the campsite from a young age, just like everyone else's.
I would also be surprised if I hadn't nipped out to the postbox leaving a child as young as 4, either asleep or safely occupied, for 2 mins. Having twins, I would definitely have left one "alone" in the house (in a playpen) whilst taking one out to the car, then come back for the other leaving the first one "alone" in the car with a sibling.
The only one of these that I would probably do differently now is the Mark Warner hotel - but I am sure that they have probably changed their childcare arrangements anyway.
I think that as a culture, as someone said up thread, we have become increasingly fearful and risk-averse. Sites like MN don't necessarily help IMHO - I remember one poster going through agonies on a thread because she needed to put her young twins in a different room to sleep as she simply didnt have any space to keep them in her room and most responses were telling her she shouldn't. When mine were small I did what felt right, without worrying about what other people thought. A lot of Internet strangers telling me I shouldn't would have been the last thing I needed.
A perfect example of excessive aversion to risk is our primary school. A few years ago regular helpers in school had to have a CRB check. Fine, and understandable. Now, you can't even walk a crocodile of children somewhere with a teacher and other helpers (eg for a church service) as a one-off without a CRB even though there is no prospect of being alone with a child. A CRB check really doesn't prove much - Jimmy Savile would have passed.
Another example - a friend was attending an early morning meeting in school, and sat her year 6 child on a chair in the corridor reading a book. The child was forced to go to breakfast club as it was deemed "unsafe" to be left "alone" in the corridor.
And one final example - last year, when he was 10, one of my twins went on an errand for me to a shop just round the corner - 2/3 minute walk, no roads to cross. One of the teachers from school saw him go in and waited outside. When he came out she gave him a real grilling about what was he doing, where did he live, did his mum know where he was (she asked this repeatedly). He came home rather shaken, feeling, as a result of the grilling, that he had done something wrong. On the one hand it was good to know the teacher cared, but on the other I was a bit cross that she had shaken his confidence and made him think he was in trouble. At exactly the same age in the 1970s, my friend and I were sent to the post office every lunch time by our teacher to bank the tuck shop takings, buy him a ham barm for lunch and 20 silk cut!! And, yes, I played out with friends, walked home on my own and let myself in with a key and made myself a snack before anyone else came home - all from juniors (year 3).
I will now sit back and wait to be told what a neglectful parent I am....