35 is not outlandish to many people on FT, and certainly not to people who do manufactured spend. But the goal is not to sell to those folks, but rather Joe Blow who thinks if he gets a new card he'll get to go to the Maldives in business class for free. Or Disney world during a school vacation week. There are still several million American adults who do not have any rewards credit cards, and more who could switch from the ones they currently have.
and each year, more and more Americans age into the credit card market.