The problem is who is going to take all these 16 year olds?
There is a limit to how many kids the likes of Scouts can take on (remember they also need adult volunteers to over see them. They can't just 'look after themselves').
Its a nice idea, but I'm not sure there is enough infrustructure to give a place to every 16 year old, so the idea of it being compulsory is nonsense.
This also ignores the point that lots of organisations won't have appropriate safe guarding training and measures in place to take on 16 year olds. They aren't geared up to this age group which needs additional measures.
Its a soundbite for the press.