alt Hacker NewsYou are obviously right that these are similar in principle: VM isolation exploit would lead to the same exposure like container-related isolation exploits.
VMs are considered vastly better because the surface area where exploits can happen is smaller and/or better isolated within the kernel.
If you are arguing the latter is not true — and we are all collectively hand-waving away big chunk of the surface area so that may be the case — it would help to be explicit in why you believe an exploit in that area is similarly likely?
I would say it's the fact that "not a security boundary" appears to be a pass/fail statement, whereas the reality is more like a security continuum, along which VMs are further than containers.