Having an OS limitation on a virtual world is more than a software limitation - it is limiting the population of interacting users. It's not like a productivity app that only runs on Windows - I can write a file, someone can write a Mac app that reads the file, OK. It's not like a Web browser that is Windows only - it would be like the Web being Windows only. That's why the comparison to Facebook (even though the software issues aren't the same) is valid. If Facebook were Windows-only, you'd have a social network of Windows users, and I'm guessing it would look a bit different.

The Second Life footage is brief in Hot Tub Time Machine, but is enough of the backstory to be mentioned in quite a few of the reviews (many of which were favorable.) I grabbed the quotes from about 30 of them that talk about Jacob, stuck in the basement, playing Second Life, and compiled them here: http://curiostrip.com/2010/03/28/jacob-in-jail-second-life-in-hot-tub-time-machine/