Well, let's see - join a forum, ask a potentially controversial question. Seems on form for me. Anyway...
I am a strong (very very strong, in fact) believer in the idea that bringing up a child is the responsibility of the parents. Part of bringing up is education and to that end, I believe that your child's education is 100% your responsibility. To give you my personal example, my daughter has just turned three. I am the 'stay at home' one and every day I make sure that I further her education. She has a strong vocabulary, has a decent grasp of maths (is able to add, subtract, multiply a little etc.), can read a little, is socially adept, has just started to do without any aids when swimming, etc. etc. blah blah blah. Obviously as a proud parent, I could go on, but it isn't relevant beyond what I have already said.
Now, I have this step-sister who has three children of her own. The youngest is brand new, so we can ignore him, but the others (8 and 7) have struggled in school and are only now catching up with reading etc. Whenever I have discussed this with her it has always boiled down to one thing: I believe it is HER responsibility to teach her children, she believes it is the SCHOOLS responsibility to teach her children.
Similarly, my brother has two sons (7 and 4), has a much stronger financial situation and sends his boys to a very good school (private) and to most external perspectives seems a model father, but even he thinks nothing of the fact that his children couldn't read before they began school, had no real mathematical skills etc.; he too has shifted the burden of that part of his boys' upbringing.
Now, we all know that schools are not perfect; over-stretched, over-structured etc., but even without that caveat, why would you hand over responsibility for your child to people who are (at least, on the first day) total strangers?
Of course, in my own situation, we have many potential problems ahead of us. Choosing to place my daughter in a school in such a way that she isn't too bored from being too far ahead, or feeling under pressure (by me) to be 'better', ensuring that she doesn't become too arrogant etc., but I want my child to have the best chance with everything in life that I can give her, and to do so, I take on the responsibility of being a parent. Should anyone do less?
So I boil my little post down to this question, asked in the title: whose responsibility is your child's education? If your child is struggling at school (or anywhere else), isn't it your problem to work at and address? I find so many people like to abdicate responsibility of their child's education and it saddens me. What do people here think? Is there anyone who honestly believes the state, or other outside system, has the responsibility; and can those people actually form an erudite argument to make me understand that reasoning?