Our Cumbria, is doing this too. Apparently they did an audit of the school kitchens, and realised that there had been a serious longterm lack of investment in the kitchens, (the school dinner money is supposed to pay for this capital investment and the wages and the food), and realised that they had a time-bomb on their hands. So they've pulled out and left the schools to it.
Fortunately for us our school has decided to continue providing hot meals, as they have a pretty high take-up rate, and it's a big school.
I'm like you Scummy - my boys have always had a main meal at lunchtime, which makes after school easier. I've told them they can have packed lunches when they're 14! But recently the school did a 'promotion' of school dinners, and parents were invited to come and see and taste ... I was very disappointed by the quality of the food they are being given ... But I'm trying not to think about it, as I'm too lazy to contemplate making pack-ups every day, let alone cooking a meal for them every evening