Here’s a handy formula next time you ask yourself a similar question:
Why does the media X?
— Because people watch / listen to / read X.
Why do people read about companies collecting data? Because it sounds scary, and it blames someone who is not them. Fear + scapegoat + victimisation of people = read read read read.
Don’t think of it any more complex than this or you will drown in irrelevant details. They don’t matter, and they never will. Read some 19th century news papers to see this effect take hold with comical clarity.
Currently, because of facebook, there is a spike of Company Y knows everything about you type stories, as well as a spike of Facebook is evil stories. These things permeate out and loose interest over time.
They love to write about scandals and problems. But if you have an actual solution to the problem, they aren’t going to publish it.
You can also see articles on court cases about some scandalous things, but can hardly find out how the case eventually turned out. And so on.
Journalism highlights problems not solutions because that’s what gets the most “outrage reshares”. The exception is some “cool new technology” that can have a story about it, but not as a SOLUTION associated to a lot of PROBLEM stories.
They particularly love to write about scandals and problems among their rivals. That's the real change here: journalists and bloggers have gone from thinking of Facebook (and other social media) as potential allies to thinking of them as rivals. Negativity sells, as you say, but negativity that reinforces one's view of rivals as evil is especially appealing. People whose own Google Ads revenue is declining because the eyeballs are elsewhere are very highly motivated, both consciously and unconsciously, to write about why those eyeballs are elsewhere when they clearly shouldn't be.
Did you miss the whole Facebook and election thing?
Example from other field: aircraft passengers have breathed compressor bleed air since jet engines were introduced in the 60s, everyone in the industry knows this is how it works, and yet it wasn't until last year, when major publishers such as Fortune , The Guardian , Bloomberg , The Telegraph  etc. happened to simultaneously run this issue, that lot of the general public learned about it for the first time, most of them having assumed that cabin air was taken directly from the atmosphere.
How can expect anything of them when I don't even know that company exists, let alone what it does?
> Why are people surprised that Cambridge Analytica, a political consultancy, did political research and affected a voter outreach strategy? None of this requires any real background knowledge, and yet the outcry seems extremely disproportionate to the revelations at hand. It seems like the Snowden reports all over again, where the world was up in arms that an intelligence agency was collecting intelligence.
This is simplifying the discussion a lot. The general assumption about both intelligence and research was probably that they stick to rules and are concerned with their own fields.
I'd guess the average joe would (before snowden at least) think that an intelligence agency is concerned with foreign diplomats and military strategists and a political consultancy does opinion polls.
It's something different if said agencies collect intimate data of random citizens without their consent. At least in public mind, that was something the stasi or similar organisations did - but certainly not their own side.