There are side effects to allowing third-party stores, or giving up on restrictions. It's a trade-off. There are advantage to both choices. I thought this was pretty obvious in my post.
If Apple was the only viable platform, then absolutely, I don't want to live in a world where I can't hack with my devices. But when you have Android, I think it's actually better for the user that a more locked down platform also exists. It's a different model to choose from.