It's not neutral. It means "as they say", as opposed to "as we would say", or "don't get too attached to what you think this word should mean, here we're using the meaning as used by the quoted, and we all know that bit everybody agrees on that".
It's a legitimate use of quotations IMO as it clarifies the text, in particular the relationship between the writer (the journalist) and the originator of the message being relayed and interpreted.