Facebook = SPAM
Let me count the ways, in rough order of most annoying down:
(1) They host Facebook pages for spammers. About 99% certain Facebook also provided the spammers with the email address to spam at, too. Some of the spammers' pages are obvious scams, but others are just soon-to-be-bankrupt quasi-businesses that apparently think it is legitimate to spew crap to people who have absolutely NO interest in their spewage, including never having been in the cities in question or owning any related products, now or ever.
(2) They show racist and unblockable comments in my face. (There are MANY other less offensive comments, but the racist ones are most offensive.) With the vast pile of comments to select from, it is hard to conceive why they pick those, but my theory is that the most unblockable ones are linked to Facebook pages that are somehow paying Facebook and thereby getting protected from the blocking.
(3) They show racist and sort of blockable comments in my face. In this case, it is the large supply of racists that makes it offensive. At least I think these individual racists are sort of blockable, but it is difficult to be sure because of how weirdly the so-called block list works.
(4) They shove 'sponsored' ads of absolutely no interest to me.
(5) They show 'sponsored' ads that might be of interest, but which I will block and seriously try to NEVER shop from.
(6) Some spam originates from Facebook accounts using the Facebook email system. Mostly Chinese stuff, for unknown reasons.
(7) Facebook allows their users to be abused by spammers and scammers based on abuse of the Facebook reputation. You can sort of say this one is outside of Facebook's control, but I say that they should be concerned even to the point of declaring war on such scammers. Of course that's on the theory that Facebook itself isn't a scam and that they have legitimate profits that they could tap a bit from to protect their own supposedly legitimate reputation. I also think the scammers are dumb and wrong about Facebook's "valuable" reputation...