Yes, I think homeschoolers do have standards, it's just that their standards are a lot higher than the ones used by public schools, which is why homeschoolers beat the socks off the public school kids. What you mean is that homeschoolers don't have standards that are set by some state agency.
The reason privates schools and homeschoolers are so much better than public is precisely because they do have standards, and high ones at that.
I'm a homeschooler. The main reason one homeschools is because you are passionate about your kid's education. Homeschooling allows the kid to proceed at the kid's maximum sustainable pace in each area