Your question: Would it be better to home school my child because he has hardluck asthma?
My humble answer: Some people simply have asthma worse than others. While asthma in itself can be a challenge, you also don't want to allow it to control you and your child. Obviously you have to do what you think is best for your child, but the education coupled with the social interaction that your son gets at school are also very important.
Even though your child is sick, you want to create as normal a world for him as you can.
On a side note, I too had chronic asthma growing up, and I can attest that school was a real challenge for me. In retrospect, I am glad that my parents never took me out of school.