There's slavery and slavery. The slavery of Roman temple girls, owned by the previous generation of temple girls and buyinmg the next, vs the slavery of mining teams sent to die for their labors, vs the slavery of sometimes well paid professionals in cities, that would be respected and wealthy of their own accord while still being owned by a particular branch of some Roman family. The slavery of america was an offshoot of the general shittiness of colonialism, taking advantage of the lesser and keeping them in their place. Hence the idea of an "uppity" man that wishes to rise to a station his masters deem too far. A more Roman idea of slavery, or possibly a merely hyper-capitalistic libertarian slavery, based in selling one's family and self when debt obligations cannot be fulfilled, needs not have the same repugnance.
It would have its own, clinical repugnance. An ever-present terror in the hearts of all citizens, from the greatest to the meekest, that the slightest failure can sell you and your progeny into horror without end.
But a scientist that is owned by a given family, station or even a specific powerful individual need not feel automatically begrudged. If they come from a world where slavery is begrudging, sure. But many would exist in the greater galactic system, and selling yourself to a guild that trains doctors and then rents them out, or sells them with an attached set of requirements of ownership might be a perfectly acceptable and even admirable position.
"Why did you bother to purchase me if you aren't going to give me the funding I require. You're wasting my talents developing this drivel. Sell me to someone of ambition. You'll have coin and I'll have real purpose"
Think more along the lines of kings, or the god kings of antiquity. For anyone not born to these impenetrable vaulted classes of humanity, they would merely be the accepted backdrop of reality. What is the difference in swearing loyalty to kings, or selling loyalty to the individual institiutions of an immortal transhuman malignance?
Don't sell yourself to a devil. Blame fate if your chosen master is cast down or sells you. For high value slaves like doctors, and the like, they would never be mistreated. You don't shit on your pilots. You grant them excellent quarters and slaves of their own. They fly billion credit machines to your glory. They are your knights. You exalt them, within their orders. You yourself remain unknowable to them.
I am certainly not advocating slavery here, of course. Whereever it raises its brutish face, suffering shall no doubt soon follow. But a fictional society can certainly have grown to accept slavery in ways that makes being bought and sold little different to a company acquiring the business that owns your business and selling it again afterwards. There would be social stigmas against buying an accountant firm and feeding all of them to a cosmic horror, and few would be willing to deal with you if they believed such a fate could also become them.
But none would bat an eye at criminals, scum, enemies, traitors and unknowns from distant shores falling into its insatiable gullet. Pleasure girls need not know of the feitsh stranglers, nor from where the cafeteria mince arises.
> Games should give kids correct knwoleges & dependencies
Kids should never touch this wonderful abomination.