It's a couple of hours later and I'm thinking. Let's come up with a brand new approach; start again ,see what I come up with.
Somebody wants to build a big fucking space station that could house enormous numbers. Why? Because there's been a very bad war. Not one person against the other, more like a clump of dozens of separate incidents that coincidentally take place during the same several years period, but taken together in that way, even though many are not necessarily related, the damage caused is similar to that caused by an all-out world war (though not necessarily nuclear). My idea is, this might happen if military technology not only got sufficiently advanced, it also became by various means available to what we like to refer to as 'developing' (ie not rich enough to buy our tv's and dishwashers, etc) nations. Imagine all those border wars, in a hundred years time, using all that astonishingly advanced weapons tech ... run for the hills ...
This could include things like genetically targeted viruses. You might be able to target them against specific social groups, particularly those with low genetic variance because the population has been relatively unaffected from mixing with other genetic groups; Icelandics, for example, are more related to each other than the rest of hte world, which might make them a target. You could even engineer a virus to attack a single individual, or members of a family, if you could get hold of their genetic material (hair, skin cells, whatever). Imagine how paranoid a president would have to be; everybody with money would be living like Howard Hughes, ultra-tidy and clean.
This might persuade some people that investing in an orbital colony might not be a bad idea. My thought is that it would be clear that the potential to actually wipe out life on earth would be great enough to provide the clear motivation. Let's posit that military tech spin-offs include radically cheaper ways of manufacturing materials both on and off earth for such space-based construction. Perhaps the station is part of an international co-operation between nations, a sort of public relations exercise in an environment where some form of mars colonisation/terraforming might be taking place.
The man ultimately responsible for building the station is idealistic, thinks he can create a utopian society ... but at the same time, people are taking advantage of tech that allows people to integrate fully with machines, possibly on the nanotechnological level. There are those, who, witnessing what people do to each other, might not entirely wish to remain human. Many of these people are regardless involved in the construction of the space station, since they're relatively suited to the environment and much better equiipeed than regular people at coping with zero gee.
Hmm. Not sure. I'll have to think some more. Live and uncut, folks!