I understand compatibilism to mean that an action can be free if it is self-determined by the agent, even if it would have been impossible for the agent to choose any other action. Consider the following analogy.
Person A is a slave who has had some sort of brain control device implanted. This brain control device does the following and nothing else. It makes the person it's controlling desire to continue providing free labor under horrible conditions(being a slave) more strongly than they desire to leave and do anything else. There are also no laws prohibiting person A from leaving, and it has been made completely clear to person A that there will be no punishment for them trying to leave. In fact their owner has told A that they will give A some starting money to help them out if they leave.
Is person A free? It seems like a compatibilist must say yes, because their continued decision to remain a slave is their own decision, it is not from fear of consequences or anything like that. They are choosing to stay because it is truly what they want to do, and to a compatibilist the fact that they couldn't "want otherwise" is irrelevant. But I think most people would have a problem calling someone in this situation free.
It just seems to me like compatibilism is a word game created just to give us "free will", but in doing so it completely devalues its own concept of free will. Also feel free to suggest any additional tags or for me to remove a tag. I included linguistics because I think this is mainly an issue of how free will is defined, but I could totally understand if many people thing that it's an irrelevant tag.
EDIT: So I just had an idea for a rebuttal defending compatibilism, so the rest of this paragraph is like me putting on my compatibilist hat for a minute. In order for the slave to choose otherwise, they would have to be free to act against their own will. But would acting against your own will really be a freely chosen action? For that action to be chosen by the agent (and therefore freely willed), the action HAS to be what the agent wills to do. Surely if you want to have a hamburger for dinner, but your parents make you eat spinach, you haven't freely chosen spinach for dinner.
So would the above paragraph be a valid defense of compatibilism? Essentially that not accepting the slaves choice to continue being a slave as free is the same as demanding a logical impossibility to define an action as free?