If we're being pedantic, you're correct. But to a pretty good approximation you can refer to the kernel features of cgroups, namespaces, etc, as LXC, and people

If we're being pedantic, you're correct. But to a pretty good approximation you can refer to the kernel features of cgroups, namespaces, etc, as LXC, and people have been doing so for a very long time. It's only recent that there were other interfaces to this such as libcontainer, and don't forget that Docker originally used LXC and still supports an LXC driver.