Back in '50s, the connection between Tobacco products and Cancer was evident.
Since '70s connection between Fossil fuel and Global warming was evident.
Yet, no one heeded those warnings at the time. With cancer rate going up, and climate becoming increasing unpredictable/extreme, people now started to take notice.
With so much information to process, Human brain ignores information that doesn't have a clear relation to a significant real world problem that immediately impacts their lives. This makes us intelligent (at short term) and dumb (at long term) at the same time.
Using a service at free of cost (at the expense of your privacy) is acceptable by majority of population as it has no significant real world impact on their lives.
If tomorrow, a huge data leak from these imbecile data hoarders leads to massive transaction fraud/identify theft that impacts a significant percentage of population and their daily lives, only then there will be massive outrage that you expect.
Till then, we are the only one who escaped the Matrix, while rest embraced it.