I had been interested in homeschooling and unschooling for years before I had kids of my own. Even as a nanny, the research helped make me the nanny I was. I did have some moments of doubt. I fell in love with Waldorf after teaching some students in my children's Aikido class. But a visit to a Waldorf kindergarten when dd1 was 4yo reminded me just how much of an unschooler I was. It was beautiful, gentle, but it was still school. I haven't looked back since.
I was never motivated by a dislike of school, but a realization that I learned so much more after leaving. My husband's school experience was so-so. He never was able to pursue what he wanted, and so he loved the idea as well.