FYI that's a direct quote from the book. I regrettably spent too much time of my childhood reading a series that ends with the protagonist thinking about ordering his unpaid servant make him a sandwich after a bloody battle.
Oh I forgot about Kreacher, I thought they meant Dobby. The whole thing is bizarre, Harry is so intent on freeing Dobby but then he's fine with every other house elf being a slave. They didn't even care about Hermione's initiative.
JK Rowling was trying to make the point that slaves should be slaves and enjoy being slaves, and the ones who want to be free are a rare exception, and anyone who wants to free all slaves is silly and cringe.
It's not the only example of extreme immorality that's presented pretty causally in the series.
I loved the books as much as anyone, but Azkaban struck me as utter barbarism even then. You're telling me that prisoners, regardless of what they were actually sentenced for, get psychologically tortured through the magical induction of deep despair until they develop a form of dementia? And this happens whether you're a murderous dark wizard or you do a bit of magical petty theft or fraud? The Ministry using Dementors for law enforcement would morally justify rebellion against it in my view, not only are they slavers they're also torturers on a scale that would make many dictatorships blush.
It's obvious that the Ministry a wicked institution, but it's also an incompetent one since the Dementors aren't even really loyal to them; they jump ship to the Death Eaters as soon as they get the chance to.