Canada is consistently ranked in the top-5 in reading, maths and science in the world. Where do you get the idea that this country is falling behind? The quality is there. Want falling behind? Look South. The countries typically ranked ahead of us employ rote-learning curriculums, specifically the Asian countries, where kids go to school six days a week and don't have summer vacation.
Okay, so a Korean kid can pass a math test before any kid in the world can. But have they had the time to go out, interact with people, and develop even a semblance of interpersonal skills? There is a place for kids like that on the job market, and that's behind a cubicle on a computer creating macro programs on excel. Employers today are more worried about finding leaders who can not only deal with and manage people, but inspire them as well. Summer vacation, chilling with your buddies, meeting chicks, going to the bar, getting drunk and meeting randoms - that's how you learn how to deal with people. I had a Korean friend who knew calculus in grade 8. Dude is in third-year university now and has never kissed a girl. An extreme example maybe, but a telling one.
Summer vacation is necessary. Every kid needs to recharge. It's also the time where you develop soft skills that in my opinion are every bit as important as the school you went to or the grade point average you had.