I think they probably did that because Priority Pass has so few lounges that even accept it anymore.

And I have found that even lounges that PP claims to work with are very quick to tell you that the lounge is full so they can reserve space for their actual business class and first class passengers.

I've been turned away more than once from a club that was supposedly at capacity when more than half the tables are empty.

So I figure priority pass thought, why not offer unlimited? No one can use it anyway.