It depends on what you mean by the term unfair.
If you're judging by today's standards, then yes, throwing two people (binded together) would be a little barbaric.
But when Hammurabi's code was implemented, this was the first time rules were really set into stone on how people should act. In their time, it would make sense to punish people harshly for doing bad things . It's not like they had divorce lawyers and and paperwork to deal with. It's also worth noting how they punish the man as well as the woman for adultery, so at least it punished both sexes, which is really remarkable given the status woman had back then.
