So many reasons. I'd be here all day if I tried to list them all. I don't have kids yet, but I'm planning on homeschooling my future kids mainly for the sake of giving them a happy childhood.
I went to public school and I got good grades. I wasn't bullied often. All the teachers liked me and I was reasonably popular with other students. I hated it, but I believed all the authority figures who insisted it was important. Even though I didn't struggle too hard in school, was always mentally exhausted when I got home. There were years at a time where I couldn't do anything when I came home except instantly go to bed (which would make it hard to sleep that night, which would make me sleep-deprived the next day; repeat for years). There were tons of projects I wanted to work on during my teenage years, notably I was trying to write a series of fantasy novellas, and even though I diligently spent almost every day after school for years working on one of them, most of them were never finished. I went to college and got a BA in 2.5 years, with an even better GPA. It was a small private college, and it was very enjoyable.
Now I'm making minimum wage at a mind-numbing temp job I could be let go from at any moment, because even after three years of job searching, I haven't found any other job I have the skills to do (and the one I've got is pretty hard for me too). I have about $45,000 in student loan debt, and my mom has to make half my payments every month because I can't afford to. She also pays most of my other bills. The only reason I don't still live with her is because I'm able to live with my DP. The only reason I'm not in therapy is because I can't afford it. I'm still working on various projects in what is now even less free time than I had as a kid. Every night, going to bed breaks my heart, because I'm tearing myself away from what I love to do, and I will be going to my crappy job in the morning. I want to be an entrepreneur, but all my 15.5 years of formal education were designed to turn me into an employee. I don't have any of the skills I need for this. I'm trying to learn them, but it's not easy when you have so little time and energy. I wish I could have learned this when I was a teenager, but I wasted my time in school, because my mom told me it was necessary. In retrospect, I should have known better than to trust her. College was fun (the most expensive fun I've ever had), but those other 13 years were a waste of my life I will never get back.
And here I'm reading articles about gosh damned unschoolers getting into freakin' Harvard! Or starting businesses, or just going straight into jobs they love. The Teenager's Liberation Handbook has an entire chapter devoted to listing out all the cool things that various home/unschooled kids are doing with their lives instead of going school. That's when it hit me just how many opportunities I would be depriving my kids of if I sent them to school.
I figure, what's the worse thing that could happen if I don't make my kids go to school and don't make them do any home school work either? They might spend 8-16 hours per day for 13 years playing video games... and then they'll be able to get a job as video game testers, which makes more money than I make. I will be a proud mama if that happens. But what's the worst that could happen if I force them to go to school? They might feel the way I felt about school (or worse, more likely) but tough it out because they trust me like I trusted my mom, then they'll get killed by a drunk driver two days after they get their high school diploma, and all those years they sacrificed will be for nothing. And I'll be kicking myself.
Coercive education just doesn't jive with my life philosophies. I'm not sure how I'm going to teach my kid to take responsibility for his own choices in life and force him to go to school.
Oh, yeah, I'd probably let my kids go to school if they reeeaaaally wanted to, but it would be with great reluctance because (a) it's a very strict schedule which constrains the entire family, and (b) en loco parentis. En loco parentis refers to the law saying that schools can act as the legal guardian of your child when you're not present. It's why a school in Arizona once strip-searched a 13-year-old girl because another student said she was hiding an ibuprofen tablet in her underwear, and while I consider that sexual abuse, it was totally legal. Is there any other situation wherein you would turn over guardianship of your child to someone that you haven't considered very, very carefully?