This article seems a little unfair to the WhatsApp founders when it suggests they should have known that any assurances Facebook made to them as part of the acquisition were obviously lies. Sure in 2018 it might be obvious to most of us that nothing Facebook says or promises can be trusted but I don't think that was necessarily as obvious when the acquisition happened and they can be forgiven for thinking they weren'…
What year would it be ok to be naive enough to think that any for profit company’s main motivation is not to make as much money possible?
For example, Facebook could've over-induldged on overlay full-screen ads or "watch this video for 30 seconds before proceeding" ads, but they chose not to.