They don't follow a standard protocol because the industry is dominated by just a few players, and it isn't in their interests to do that since they want to make customers dependent on them. The industry is dominated in part because the fingerprint tracking creates extra overhead that's harder for smaller or starting businesses to deal with.

They don't just have to maintain a database. They have to handle all of the logistics of accurately collecting and entering the data for it. They need legal counsel to get it right. They need to work with distributors and/or retailers to get an idea where they're going so a fingerprint can be linked to a retail purchase. They have to deal with the inevitable subpoenas at a minimum, but I wouldn't be surprised if they fulfilled requests without a legal order. It becomes a lot of extra labor beyond just making and selling printers.