> Personally, I lived for summer vacation until I was like 14. If you took that away, it would have negatively affected me, and many others.

I honestly think this is a product of society and not some intrinsic driver for kids in school. Would a 14 year old me like it if someone told me summer vacation was canceled? No. But if I had been in a system with a shorter summer vacation from the beginning, I don't think I would care too much.

Maybe I'm biased, but my best times with friends were usually during school months. Summers were usually spent playing a lot of video games and going on boring camping trips with various relatives. At the time I loved the break, but I can hardly remember a summer where something really interesting and eventful happened.