I highly recommend a Second Life-like experience for any and all members. It doesn't matter what it "is" or what "content" there is within, it matters what you "can" do. How you feel about what others have done, or what you think it's about, will be as wrong as trying to assert what life on Earth "is", or what "content" there is within. You "can" go to space, regardless of mass non-participation. You "can" utilize a virtual world, regardless of current utilizations of it.
If anything, there should be a native population of 3D Modelers, Texture Artists, Animators, Script Coders, and more. These are also people who are likely fluent in living in a virtual world(sometimes, it's all they have due to disability or a heavy, home-bound workload - very much like what we might be stuck with in space). There are science-fiction creations abound, some of which may have been designed with utmost care for realism, others that are simply aesthetic for selling purposes. It is a very commercialized world upon most traversals, yet an isolated commercialization. There are likely tight-knit bonds who don't wish to be interrupted, or lands that have been waiting for a flood of newcomers(some even functioning without owners). They have their own borders which they can lock up tight, or who let any and all(this includes controlling more than just entry: animations, sizes, abilities, etc).
There are surely entire space-station/ship worlds with advanced simulations, or again just aesthetic touring areas. There will always be something to learn from a group of people who are trying to simulate space living in-depth, in their free time. They have probably had more arguments on what is realistic in that sense than we have, and they may even be stored in virtual books. The analysis of the worlds themselves are akin to a book, with all the possible inner-workings of the scripts and the 3D constructions in general.
Also, it doesn't hurt to have a virtual platform where you "can" explore, even/especially the things you disagree with. Even post-Asgardians may end up lingering around and contribute continually, unlike what a text forum provides. I have been lost for hours in that world, flying through what felt like miles and miles of creations that were now abandoned yet must have taken so much to build, and yet know that I was barely scratching the surface of what existed.
I am not sure if "Second Life" itself is worth it to invest all-that-can-be-done-within, but I do think an upgraded, open-source, custom version would be heavily important, especially to those who actually go into space... the availability and entertainment of wandering around even the largest and open of spacecraft will warrant a high desire for a massive, shareable, and persistent virtual world.