title text: “The universe is probably littered with the one-planet graves of cultures which made the sensible economic decision that there’s no good reason to go into space—each discovered, studied, and remembered by the ones who made the irrational decision.”
Initially (economically) irrationally decision, anyway.
I used this trope extensively in developing the Eldraeverse; of course, those single-planet cultures which find themselves overtaken by the expanding edge of the Associated Worlds do eventually get into space. Only to find themselves relegated to playing catch-up in a galactic society that sees them as eternal second-placers, but, hey, lack of ambition has consequences.
[Originally posted elsewhere, 2011/5/3 – I ran across it again, today, and dammit, it’s still relevant.]