It's quite entertaining to watch Venmo try to explain away the default behavior of their app, which broadcasts users' transaction info publicly. The unnamed PayPal spokesbot cited in that story claims the service was "designed for sharing experiences," which is a delightful wad of claptrap devised in order to spin the fact that they must want to publish this data about your finances in an attempt to attract new users.
Everything in Silicon Valley may "need" to be a disgusting "growth hack" in order to keep the VC Overlords happy, but treating financial transaction data like any other form of user-generated content is a new low.