This shouldn't be something you pay for, especially if you already own the game. It's an internet based app, of course it has to have online access. This isn't even a game, so the DRM aspect is not relevant here.
This isn't the holy saviour of gaming that everyone wanted it to be, but it's a fine game. It kind of reminds me of Watch Dogs, which was another game that got overtly hyped and later became infamous for it's lackluster release, but despite it the game was enjoyable, even if not the most revolutionary. If you set your expectations right, you'll enjoy it.
