The government needs to protect children before they're maimed by careless or stupid parents. A government agency letting you know what it considers risky behaviour is a good thing, so long as they don't set it too restrictively.

You may say "but what kind of fucking idiot would leave an 11 year old child at home alone for more than 24 hours?"

Here's a story about a woman who left her 11 year old boy alone at home while she went on a three week holiday.

http://news.bbc.co.uk/1/hi/england/2601747.stm

That article also mentions the case of a twelve year old boy who was left alone for a fortnight.

Thus, when CPS get a report of a child alone at home it's a good idea for them to ask (but not formally; not as part of taking action) if the child is safe or if the parents are going to be back that day or not.