I don't think IABU but this is not sitting right with me.
I live on a new build estate, my house is right at the start of the development.
There is a boy aged 6 who lives at the furthest back end of the development, however, he is playing outside at our end until 9.30 ish most nights, last night it was 10pm!
There is absolutely no way that his mum can see him from her house, he is completely unsupervised.
I would say it's safe enough apart from cars but surely not for a 6 year old?