They can have a paper process still. It's a bit harder, but you can have someone go up to the counter, show some form of ID, sell a season pass with the name on it, and have them show some form of ID when they're not using a smartphone ticket.

Not a difficult process, blocks scalping, and is unwelcoming enough that it'll probably only attract the people who can't or don't want to use smart phones.

They already had a ticketing flow they invested money into altering it. They could've put in the absolute minimal effort to keep some kind of flow for non-smartphone users.