Your comment is written weirdly so I don't really get your point but I think you are being sarcastic and calling the dude you replied to a bootlicker. But that person actually had a valid point here. Login with Facebook is a relatively well received feature for third parties. Why would a first party platform use a bespoke solution?

Hating on Facebook has now become a conformist thought pattern. There's plenty of Facebook to hate if you look, but most people just blindly apply their dogmatic hate everywhere.