Publishers will like a database because it can be modified. If they were forced to implement such a system (thus abandoning all 'sell the same game to the same person twice' for different platforms), they'd oppose a blockchain system hard, since it would make it pricier to:

a) publish seven bazillion versions of any given game
b) revoke ownership of games just because it's cheaper to do that than honor the deal they made with customers
c) correct any data-fuckups they will inevitably make because they went for the cheapest route possible to implement this, and it went pear-shaped from day 3 onwards