Yes. And I don't think you should need a certification to teach your children either. Too many public school graduates are illiterate and innumerate, and they're taught by certified teachers. Homeschoolers blow thier public school peers out of the water. What does that tell you about the need for certification?
Home schooling IS allowed in US, Canada and UK and many other countries.
There are many reasons for home school a child, from health and learning problems to just the right to give your child the opportunity to learn with her own learning style and at her own pace, respecting her needs and interests and giving her the opportunity to develop all what she needs in a loving and caring environment.
Not all families should homeschool, but that is like saying that not all families should have children. Not everybody is healthy and prepared or willing to accept the huge commitment of being a good parent.
Schools are not jail, they were put there for many reasons, but as many other institutions, not all schools are doing great, nor are they great for ALL the students.
More than that question, you may ask a more specific question where you expose your reasons for being against home schooling. At least, people who is against public school system talk about their reasons and they sound very logical and reasonable.
Home schooling should be allowed. You have people out there that want to teach their child on their own. There are people who can't focus and have a hard time learning in a school environment. For example, my fiance couldn't go to regular school because he was too much of a disruption to other students and he was too distracted. There are teachers out there that don't know how to tolerate certain people and only the parents know how to do it; so, it's only best that the child get taught at home where the child can be disciplined appropriately.
I was home schooled through eighth grade. Of course im a bit biased, but i feel that i learned more through studies at home then i did through high school and college combined. Not necessarily more information, but higher retention of the information taught. In my opinion, the public school system has repressed the desire for knowledge and achievement to a simple desire to learn only what is needed to pass a test, then purge that information for the next test's information. In addition, I loved reading before high school, then i was required to read novels that pushed political agendas or the personal agendas of the teacher, not classics like Shakespeare. I no longer enjoy reading in the least. Now reading is a forced absorption of unwanted knowledge for me.
Homeschooling allowed for a freedom of thought, to which i attribute all of my successes thus far.
Also, outlawing such would be unconstitutional. It takes away freedoms from people that do not negatively affect others not involved. Basically, outlawing it would be taking away liberties from one group of people because the other group simply doesnt like it.