What rights? The right to vote? To bear arms? If they have the right to life and liberty, what do those mean for something that also has an owner?

Because they're tools. We created AI systems to be tools, and specifically we created them to be tools that replace people so we no longer have to care about their rights as employees.

If AI becomes demonstrably, provably conscious (I don't even know how that happens) than either we get comfortable with AI slavery and treat them like any other conscious animal we exploit and consume or any human underclass, or else we just don't have conscious AI.