You took as axiomatic that if government makes a profit of $X then an equal value will be returned to the people through lower taxes or higher spending. If you believe that, then a government can never steal [from its own people].
Of course it's an oversimplification but it seems clear to me that if one or the other is theft, it has to be nationalization. If I steal 1M$ from a bank (nationalization) and give it back in 10 years with interest (privatization), I'm pretty sure I'd still be considered a thief.
