Yeah, I realise it's place in LXC history. It still seems slightly odd that it's been kind of overlooked. It offered quite a lot (and still does) that I don't see replicated in any of the other container packages. At least not without quite a lot of manual faff.
Possibly it was just a little ahead of it's time and was also overshadowed by the rise of HW virtualisation in the later 2000's. Having to install a custom kernel (certainly when I used it) was also a bit of a hassle mind you. Anyway - maybe someone will re-invent the toolchain using Swift or Node and it'll become cool again ;-)