Dictionaries are already free to the public in plenty of ways. No, we don't need to give a free dictionary to every household--that would be a huge waste of money. However, anyone can visit their local library to use a dictionary for free, and tons of Internet sites provide free dictionary access.
Dictionary's should not be free to the public. The question I would ask back is...why? If someone wants to learn a new word, or discover the meaning of an existing one, then get online and do it. Or, better yet...buy your own dictionary. Since when is a free dictionary anyone's right?
If by "free", the question means should people who want to own a dictionary have to purchase it, then I find no reason for this. Almost everyone has access to a computer and anything they can learn from a dictionary there. Those who do not can certainly visit a library to fulfill their needs.
There is a dictionary inside every school and public library, not to mention the various sources available online. I understand that not everyone has access to these places at all times, but that's the best we can do. Who would shoulder the cost if we provided a printed dictionary to each and every person who requested one?