The technologies that enabled containerization (namespaces, chroot, and cgroups, and their predecessors on BSD/Solaris) were created specifically for security and resource isolation.
The people who came up with "containers" as we know them today found a clever hack: combining those security-oriented tools with a filesystem-in-a-box and packaging system allowed people to package entire OS userlands and run them pretty deterministically in multiple places. The security isolation properties of namespaces/cgroups/chroot also happened to provide increased determinism.
And I'm not criticizing that; containers are a very clever hack that solved a problem a lot of people have. I use them every day.
That said, the fact that containers became so ubiquitous in the first place speaks a completely self-induced problem that we didn't need to have in the software engineering community. That problem is, unfortunately, human/incentive-related in nature, so containers are probably the best we're going to get--problem is, they're not that good.
