Colloquial versus contract. It's sold as unlimited, because for most people, it is. Similar to how salt and pepper at restaurants is practically unlimited, even if you can't demand they hand you all the salt in their kitchen.
In practice, marketing as unlimited to suss out the use distribution before capping it where it becomes uneconomic seems to be a valid strategy. (The fraction of users curtailed plays into perceptions of fairness.) With that framing, this story has no bad guy.