One reason it's not very popular (from my experience): Docker Desktop for macs, which makes Docker experience on mac os feel somewhat close to native. Meanwhile, to use LXC you'd have to work inside VM (Virtualbox or similar). Last 3 companies I worked for (in London) were almost 100% mac os (which is a little sad).
If you use "kind" to create a K8S cluster on MAC, using LXC is totally transparent. You can just load regular Docker images via "kind load docker-image". It even takes less RAM than minikube, because the running Docker VM is re-used.
