From the conclusion:
>It is not hard to consider the chroot() system call a security feature. In theory, it sounds great, but if you really take the time to understand what is going on, it is not really a security feature, it is closer to what we would call a hardening feature. It might slow down an attacker, but in most situations it is not going to stop them. We are dealing with a situation where calling this a security feature is likely more damaging than not because it creates a false sense of security. It is human nature to let our guard down if we believe we are safe. Using chroot is no safer than not using a chroot. You would be far better off investing your resources into a custom SELinux policy and ensuring your system is properly hardened. Good security has no shortcuts.
I think the point is that you shouldn't consider chroot the only or best option for securing your system. It's just one tool in the toolbox and needs to be understood properly and not trusted blindly as the solution for all security vulnerabilities.