Also, GWG: Dogs are considered property under the law. And were, in fact, 'made'(in a manner of speech) to be subservient to humans. Is that so wrong?
Considering that dogs are not sentient? Not so much as it would be for the troglodites. Also, we're not just enslaving a species under your proposal--we'd be creating a race for the sole purpose of enslavement.
I'm not saying we allow our people to mistreat and murder them willy-nilly(would you murder your dog(if you had one)?), but we would do well with a race of workers to tend to menial tasks.
Why on whatever planet this game is set on did you call them slaves if you didn't imagine using them anything like slaves?
Hell, if we can build them to have no attachment to family members, and love working, it'd work out fine. In other words: is it wrong to force a robot to work if it's been programmed to love work?
No, but it is wrong to program a fully sentient robot to love work.
"Of course whatever Dark wizard who created them in the first place was evil beyond compare, but that was no reason to deny the poor creatures the servitude they were bred to enjoy." --Harry
Potter, Harry Potter and the Methods of Rationality
It would be wrong to force them to like working their hindquarters off and then exploiting them. Just giving them menial jobs is fine, but NOT if we force them into slavery with their psychology!
Before I go on; you used sentient in an odd way. Perhaps you meant sapient?
The power of a being's soul is seemingly tied directly to its capacity for free will. Troglodytes have weak souls. Therefor they lack free will in all its power, falling somewhere between really weak willed humans and stems(which, by the way, are essentially undead analogues) in their ability to defy us. And dogs are arguably sentient. Can they suffer? Can they experience their own little life? Yes? Good enough. And how is creating a race for the sole purpose of having workers around any different from breeding wolves into servitude? Actually, this brings to mind a curious idea; life-long body guards/manservants for our people? But I digress.
Now, are they sapient? Which is what really matters. I think not, or at least not in any way beyond a particularly wily coyote. It's obvious they're lacking in a multitude of 'higher' brain functions, or at least a good chunk of self-awareness. They're probably between dogs and orcs(though orcs may just be stupid) in that regard, to be honest. How would making them enjoy working be so evil? Your quote itself illustrates the point: Why deny a being built to take pleasure from its work the pleasure it derives from working? Perhaps building them that way could be construed as evil, but then again, Krait has his labor force, and he's a pretty okay guy.
Also I called them slaves for one reason: Because it was the first term to come to mind(all are slaves to Armok). 'Unpaid workers' had too much of an indentured servant feel, and they're not working to pay off a debt. 'Robots' is a term that only really applies to Stems, and implies a great degree of disposability. And just plain old 'workers' implied they had more free will than they do now. Perhaps the easiest way to describe it would be 'slaves with rights'. Like permanent indentured servants.