The article mentions this but links to a Google search as "proof." Even VM's have lots of ways to escape these days.

Chroot vulnerabilities have been discovered and fixed over time, as any security issue in an operating system is. It's not accurate to say that they are insecure in a blanket fashion especially these days. My opinion is that we should be using Unix as it is meant to be used, as on operating system, and using its time worn facilities meant for purposes such as security and sandboxing. They are very well tested and the solutions are baked-in and generally pretty small in terms of both code and overhead when compared to spinning up a VM, for instance. There are arguments for using VMs for security and scaling but they don't always win over just one modest local server in either domain. We're not all serving Google search after all.