I think that is missing a big point.
I was a big FreeBSD user, using Jails a lot.
Docker is solving the distribution/setup/resource logistics with a good ux. Jails doesn't solve these problems.
Technically Docker is a huuuuge mess.
Linux has lxc, wich is much closer to Jails afaik.
You get a VM-like container, owned fs and setup your "os" yourself. This has pretty much bare metal performance.
I love FreeBSD, but I'd also enjoy some modern comforts in declarative deployment.
