Why are there so many failed terraforming projects that have completely stopped, when minor effort could make them viable again?
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Or is that just a gameplay/story segregation thing and it's considered much more expensive to build reflectors/shields/shipping infrastructure than capships?
I think 1, it's more story conceit and that the massive fleets and oodles of credits the player can acquire, and the relative ease of creating size 8 colonies in just a decade or two of game time, are not really reflective of the lore -- the player is a superman.
But also, 2, why is the entire human civilization in 2020 paralyzed and unable to do anything about the changing global climate and other ecological problems, when (relatively) minor effort could solve them (regardless of your stance on their cause; geoengineering is eminently possible, if risky)? The answer is that everyone has their own different preferred solution, people refuse to compromise, and it's a coordination problem where each individual person/city/country/corporation is better off doing nothing and waiting for someone else to try to solve it, rather than working together selflessly and with compromise. And there's always the possibility with any given solution that you fail or somehow make things worse. Maybe there's a big debate in Mairaathi scientific circles around how many shades need to be pulled in, whether to repair and reuse the existing ones or try to build new ones, and how to coordinate which regions should be shaded and which shouldn't, meanwhile there is political debate about who controls the shades, who pays for them, etc., and so in the meantime, nothing gets done because humans suck at solving this kind of problem naturally.