One interpretation is that it's satire. Another is that it's an attempt to trick dictators into planting the seeds of a republican revolution. A third is that

One interpretation is that it's satire. Another is that it's an attempt to trick dictators into planting the seeds of a republican revolution. A third is that, while Machiavelli is a republican, he's also a realist. He understands that, sometimes, there will be a dictatorship, he accepts this and he's offering genuine advice to autocrats. That his advice is cold-blooded is a reflection of his concern with concrete reality as opposed to ideals and his belief that a dictator trying to be good is worse than a dictator who ruthlessly pursues his self-interest.