Yes, my OS is slightly "weird" for reasons I did not choose. Funny story: while I was trying to figure out what the hell RVM was doing, I mostly ran across people running OS X who had the same setup: 32-bit OS on a 64-bit chip. (And for what it's worth, Python native extensions build for the architecture of the Python executable — you know, the thing that has to load them — rather than the architecture of the machine.)
I never complained that it didn't work with an old database. Ubuntu's versioning was just a fun surprise. I don't see why it wouldn't work with Postgres 9.1; I just figured I'd do the upgrade while I already had my foot in the door.
Maybe if installing Rails apps is still a huge headache after the fourth or fifth time I've done it, something is wrong with Rails. Maybe.
I have a fairly mundane server running the latest Ubuntu LTS with all stock vendor packages. If your app is such brittle crap that this is the "server from hell", well, it's no wonder everyone is using Docker.