Agreed in general, but I'm not so sure Docker should be expected to support installing a complex container manager into a 32-bit userspace on a 64-bit OS. They'

Agreed in general, but I'm not so sure Docker should be expected to support installing a complex container manager into a 32-bit userspace on a 64-bit OS. They've done a lot of good work (doing the things that you've called out above), and I personally think it's fine to say that the tool is mostly for the kind of commodity just-imaged OS that typically runs in the cloud. Putting Docker on a snowflake server doesn't seem like a great idea even if it works.