The pitch was that Ripple, the company, was going to sell XRP, the cryptocurrency, to the general public in order to fund all of their growth. Then, when banks ostensibly adopted XRP for their banking needs, the banks would be forced to pay exorbitant amounts of money to buy the artificially-scarce XRP from all of the speculators who got in early.

Everyone conveniently ignored the fact that large banks are not dumb, and they had no real reason to use a currency literally invented out of thin air to power their transactions. If banks really wanted to use cryptocurrency to trade among themselves, they'd obviously just roll their own cryptocurrency. Or they'd just copy-paste the permissively licensed Ripple code and call it something like BankCoin. No one could ever give me a good reason why banks would have no choice but to buy up arbitrary XRP from general public speculators.