Why must we all learn the same thing at the same time?

I am one of the 200 'Globe and Mail School Council' panelists chosen from across the country to inform G & M journalists on matters concerning education.  It sounds important; you get to weigh in on timely issues of the day. I must say, I was rather discouraged at the first big question they asked:

Where do you stand on the practice of kids being educated at home? When parents become the teacher, and the home becomes the classroom - does it work? And beyond that, how can home schooling improve?   

Why did they have to start with picking on homeschooling?  Everyone and their dog has an opinion(usually mis-informed)  about homeschooling. “Oh I know homeschoolers who think Indians deserved to be put in reservation camps.” “Yes, yes. They are academically capable but they are weak when it comes to conflict!” “Oh socialization this and socialization that.”
Hello? When was the last time you spoke to a homeschooled kid?
You know what I feel like saying on that council?  I feel like telling most people to go get educated about homeschooling. Don’t just spew out your random notions.

When are people going to get it in their heads that homeschooling is not mom and child locked together in a basement, no other people involved, hiding away from the rest of the world, lest the child be contaminated by outsiders and different people and strange, fanciful  ideas like evolution and homosexuality?
Reality check:sooner or later if you are living in the world-yes even that chained up homeschooler will eventually have to emerge from the basement- you are going to bump up against ideas and people who are different from you. Like any schooled kid, you will be open to new ideas or you will not.

Do schools teach tolerance? Hardly. Do they teach you to respect other people? While authorities are looking. I am sure that all the racists and bigots out there were not all home-educated.
We celebrate cultural diversity in Canada. Why can't we celebrate educational diversity as well?
 It is pointless to say that had your child been homeschooled, he would have missed out on the chance to play in the school brass band. So what?  Life is such that another opportunity, a different opportunity would have arisen instead. Maybe he would discover a love for the guitar and then gone on to form a band of his own.
I can't understand why so many school people are indignant of and even hostile to this idea. Why must we learn the same thing at the same age at the same time?
Is it because it is easier for the adults to classify and control kids? Is it easier to interact with kids if you know what grade they are in and what they supposedly have 'covered?'

Read here for the 'article' the G&M came up with.