LXC is deprecated from RHEL 7.x onward.[1] Doesn't that relegate it to "an Ubuntu thing" status?
At some point they were being made fun of for being slow, old fashioned, stuck in the early 2000s. They have to be obviously for stabiliy, but you know word spreads. So around RHEL 7 time they went all crazy trying to show the tech world they are still hip and cool, looked around, saw what the cool kids were talking about -- Docker. So they got themselves some Docker. So now it is Docker, Docker, Docker all day every day.
Naturally now it is uncomfortable to say "yeah well LXC is there, can use that as well or instead of Docker", but that would kind of backpedaling on their Docker bet by having something that competes with it. So they are stripping it out.
Its not like the two things are even targeted at the same use case. Libvirt LXC is designed to make containers appearvlike VMs and is pretty heavyweight to set up. I always preferred using raw kvm or LXC to wrapping it in libvirt which just gets in the way.
Docker is largely for running single applications with lightweight easy to use setup so you can run it constantly.
Isn't libvirt just a controlling wrapper? It is basically an abstraction over various VM-like technologies: KVM, Xen etc.
"Future development on the Linux containers framework is now based on the docker command-line interface. libvirt-lxc tooling may be removed in a future release of Red Hat Enterprise Linux (including Red Hat Enterprise Linux 7) and should not be relied upon for developing custom container management applications."