Earlier quoted context omitted.
I'm not sure why Google would care to know those things. The most profitable form of advertising is a direct search. "Bears tickets" is advertising gold. Joe liking the Bears on Facebook is not on the same level. Google might get incremental value on having the additional data but I don't think it's worth the reputation hit.
There's a whole spectrum of user data with varying value to advertisers. Google already rocked search big time and now they're on to the rest of the online advertising budget. Ad networks (like me!) use demographic, psychographic, and behavioral data to target most display ad campaigns. I have run campaigns specifically sold as "market to Nigerian immigrants living in America" or "moms 25-35 interested in beauty prod…
Not everyone in the world can be assured their human rights and exposing personal information can lead to persecution. Therefore, there is a risk attributed to this data collection, at least for some. Not everyone is willing or able to take these risks.
While I can agree that this data may be useful for both customer and advertiser, its potential misuse should not be ignored. And when these networks deny the use of pseudonyms, they force their users to take (unnecessary) risks.