Deciphering Facebook Policy Riddles

So Facebook pulled a Trump campaign ad from circulation. I thought I was having a brain fart because I could not fucking understand why:

Facebook’s ad policy prohibits “content that asserts or implies personal attributes,” including, among other things, "direct or indirect assertions or implications about a person’s ... gender identity."

I started wondering what in the hell this could possibly mean. Thankfully, Facebook explains:

“Find black singles today.” is ok

“Meet other black singles near you!” is NOT ok

See the difference? I stared at this for a good five minutes before it clicked. The operative word is "other", which implies that the ad knows you are in a particular demographic. I'm still confused as to why this is an official Facebook policy. It seems in place more to cover Facebook's nosy ass and not spook folks into realizing how much information they know about them than to actually legitimately protect people's privacy. You apparently can still target demographics, you just can't let people know that you are targeting their demographic. Am I reading this right? What other benefit could this policy possibly have?