They didn't chose it based on privacy. But they have an expectation of privacy. The post office doesn't read your letters, so why would you expect Facebook to read your messages?
It's difficult to understand for the average person just how much Facebook knows about you and what it can do with that information that isn't in your direct interest. At best they think it's weird how long-lost acquaintances show up as suggested connections, at worst they only notice when Facebook does something directly useful to them.
Sure, you can blame the users, but that's kind of unfair if you consider what kinds of markets WhatsApp already dominated before the acquisition.
It's difficult to understand for the average person just how much Facebook knows about you and what it can do with that information that isn't in your direct interest. At best they think it's weird how long-lost acquaintances show up as suggested connections, at worst they only notice when Facebook does something directly useful to them.
Sure, you can blame the users, but that's kind of unfair if you consider what kinds of markets WhatsApp already dominated before the acquisition.