Think of it like TV
I might agree (sort of) - I think a lot of users are more than happy with 'Free' in exchange for ads and usage tracking, they don't see the value on what they using to pay for these services, and won't until they get hit by an identity thief or some other fraud.
Perhaps companies feel their product would be less attractive if consumers knew how much of their activity was monitored - most people will click through without reading impatiently anyway.
But TV? It's not usually that free down to just ads, there's channels and who charge subscription and serve ads.
And the rub is, even with all this data collection, companies who pride themselves on targeted advertising still seem to be wide of the mark - The fact that these companies think their 'expertise' might be useful in medical diagnosis scares me.