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.
Bitcoin is a decentralised crypto currency and because of its decentralised nature only there are many organisations, big multinational companies, even the governments of many nations are saying rubbish about the bitcoin and they are also very right at their respective place as no one wants to bring any kind of illegal activities in their organisations and Facebook is one of them but the best part is when Facebook banned crypto ads from its page, it leads to deflation in the valuation of stocks of Facebook and this simply signifies that how bitcoin is important for people.