Facebook doesn't seem to have too much trouble attracting talent. (Personally I have little interest in working there, but PHP is only a small part of why.)

I think it was the assumption that it was a joke (as another commenter pointed out) based on what was written. Nothing about the post was NSFW, including the link. In fact, if anything in the post was NSFW, then the problem lies with the place of work, not me.