I doubt that the amount of new information and thus potential monetary vlue they gather from face recognition technology is worth a real lot. It is relatively expensive (in compute power/infrastructure) and will not uncover previously hidden/unknown links in the social graph as the people in such photograph probably already were friends (within a few degrees).

As a means to increase user engagement (who then will volunteer more information by posting, liking and clicking around, especially on ads), I'd guess the same, that this also doesn't add much.

What's more, it's not just a one time fine. It's an order to stop certain actions. If they do not comply, then they will get fined again and again.