I absolutely agree with that, and don't really see anything controversial in that statement.
I also think that Google has created more value for more people than probably any other company in history.
If they are in fact an advertising company (which we agree) then the value they have created has been extracted from more people than probably any other company in history.
Advertisers don't create value out of nothing, the value comes from distracting people and devaluing their browsing experience. Even traditional "big enterprise steak dinners" advertising companies have worked this way, selling 30 second TV spots and filling your mailbox with junk. Google is able to extract a lot more value than ever before only because the Internet contains so many users and so much content that they can do it in such tiny units that it pretty much goes unnoticed. (Until it passes someone's personal threshold for annoyance, and they write a blog post about it.)
My personal (selfish) opinion is that it is sad, and that the overabundance of advertising on the Internet has made it a worse-off place for me. My browsing is inefficient, and my search results are less relevant, and my time is ill spent (either scrolling past things I don't want to see, or waiting for pages to load, or actively installing ad blocking software). Yes, I know I'm being selfish. Still, I do see it as a necessary evil, and I don't see how things could be any other way.