Facebook is not against Bitcoin but rather intends to avoid the situation of misleading its community members through its paid advertisement. Users of facebook can post crypto and Bitcoin related topics on facebook without any penalty.
Yeah, most likely nothing against Bitcoin, rather than ICO-s, scams etc.
Also we do not see any ads for bitcoin on face book. It is only the ICO which are being shown on Facebook and of course some evil minded people use to scam people by giving attractive ads to the face book users. All in all it is a good step for bitcoin community.