i don't know who those people are.
Those two:
https://www.civilization.com/us/new...--the-story-behind-pac-leader-daoming-sochau/
you're assuming that the people on earth *know* that it's going to take 400 years. the closest solar system is less than 4 and a half light years away.
there are at least eight others within 15 light years, so it's pretty probable that the seeding ships checked those out first before passing them up.
Why would they do that? Thats a huge waste of time and energy (not speaking of the risk involved). You'd analyze possible colonisation prospects with telescopes (atmospheric composition + indicators for life, gravity, rotational speed, temperature, presence of magnetic field...) build a huge seeding ship, packing it with all of the useful things you can think of (and then some more for redundancy, since you might only have one shot at this), freeze the best and brightest of your people, and then let that package propel itself for 200 years, reaching a fraction of lightspeed, and then decelerate for 200 years. If you could do it faster, you would, especcialy knowing that other factions are shooting for the same planet. No matter the scenario, when time is short you'd always send the seeding ship without waiting for the probes answers and you would try to keep travel time to a minimum (because electronics don't do that well under the hard radiation in space and many systems like the ships drive would be subject to attrition). Its a sprint not a sightseeing tour. In the meantime you build smaller ships with useful provisions and slightly stronger drives, so they would arrive roughly at the same time as the seeding ship (normally you'd park them in orbit and let the colonists coordinate reentry, but we are speaking of Civ, and therefore need goody huts), marginally increasing the main missions success. Any robot probes would take roughly 400 years to arrive too and keep in mind that the people on earth know that the launch window in which humanity is able to support such a seeding effort is closing fast due to ressource scarcity. Its now or never. This ressources will lack humanity in the years to come, therefore from a strictly utilitarian perspective it is a very unwise investment (humongous negative ROI). But one that could secure the very survival of mankind.
and i don't see what this has to do with WWII, other than that they both involve devastation (and even then, WWII has nothing on this).
Not with WWII per se, but it happpeneed during WWII that the London families in fear of german air raids brought their children to the relative safety of the countryside while they themselves continued to work in the capital. They could not all flee to the safer countryside so they at least saved their children. Not expecting return on investment, because if their action would have saved their childrens life it would be because a bomb would have hit their house in their sleep and they would be dead anyway. See the parallels? Not? Just stop looking for nazis and soldiers in that simile. See it now? At least read Narnia.
do we really know for sure that everybody in-universe knows it's going to take 400 years?
thats a basic assumption since its basic physics the street children of the Kavithan protectorate could explain to you in excruciating detail. Yes, we can assume that most humans know the details of the seeding.
again, you guys are basing your assumptions on everybody knowing that it's going to take 400 years. but, even if that's the case, i still disagree that nobody wants a return on their investment. for example, if number 2 is true, then that usually implies that they expect something from it, even if it isn't directly from the space mission itself. you're looking at things in a vacuum.
Yes, we assume that. And with good reasons, physics among them. The fact still remans that the huge investment has to be compared to other investments in term of profit. The seeding takes just about the whole production capability of the factions and yields a bit of goodwill and maybe some useful tech. Investing these ressources into the economy, or into intrasolar settlement and mining operations would yield far higher ROI for the people of earth, in which case you'd have to compare both scenarios to calculate the "economically rational" action. Compared with other possibilities the seeding yields far less than any other possibilities, therefore the seeding is a net loss for anyone staying behind. The only really big gain is the survival of mankinds offspring, and thats not very tangible for the people back on earth.
Lets put in terms, even business administration students would understand it: You have an apple. You could give it to your child to eat. You won't compare this option to letting it rot in your cellar (at least as BA student you would not). You will compare it to the cost of selling it / buying a new apple to replace it. Then calculate the ROI of your options under the assumption that it is the last time you see your child. Ever. Have fun