I think they lost that argument when they started Google+, going into direct competition with Facebook with a comparable product, albeit unsuccessfully.
If anything Google is more sinister to me, with a much broader reach than Facebook into areas like mapping and navigation, personalized ad tech, personalized search, mobile OS, PC OS, web analytics, etc. etc., all at least partially geared towards data mining.
Not defending Facebook by any stretch, but "my dictator is not as evil as your dictator" does not hold up for me.