They went after Microsoft for similar reasons- they were using their operating system (Windows) to push other products (like Internet Explorer), which limited competition and hurt consumers. Now Google is integrating Google Plus into their search, and ignoring sources like Facebook and Twitter for that same positioning. It's pretty clear cut to me why they're doing that.
The other issue here is that the author of this article is the one making this connection, and adding his own thoughts about it. No one from the FTC is saying they're trying this second path because the first one didn't work- in fact, if you follow the links from this linkbait blog post, you'll see that he's filling in a hell of a lot of blanks himself. The FTC is still pursuing the original issue, they're just also going after this second complaint at the request of Microsoft and Apple (amongst others), who think paying 4 billion dollars to add wifi to their phones is a bit ridiculous.
https://plus.google.com/116899029375914044550/posts/24uqWqvA...
Seriously, try the browser extension or tools setup on the link I sent- they use Google's own results, they're not just injecting things randomly.
If you are not showing high in Google and you don't want to pay, you are fucked. You don't exist for the 85% of population.
It's not like consumers make rational decisions. They are habituated to use Google.
PS: Searchers are not Google's consumers, they are their product. Advertisers are their consumers - they are the ones who pay them.
So, nice try Microsoft?
Tell me how Bing is better at solving this problem.