Look, in the end, it's still up to them to clean up the mess.
The diplomats don't want civilians; they only want to ransom a few nobles, and Mecha Masters are also on the list for ransom. As for soldiers, if they can be exchanged, do it; if not, then they're abandoned.
The Empire has a large population. They can easily produce some clones, nurture them for over a decade, and send them to the battlefield. They don't care about morality, only profit.
It's also because their internal power dynamics are intricate.
The diplomats have very limited resources for hostage exchange, at most just a few.
But the Ten Stars Republic isn't so easy to deal with; you think you can just come and go as you please?
With that little offer for exchange, that's not happening.
If you want to ransom, you must ransom them all. Whether you take them away or not is another matter, but the per-head cost must be complete.
Otherwise, after taking care of these people for so long, should we not be paid?
