I am a retired newspaper journalist. What do you know of journalism? 
I do! A journalist is someone who writes or distributes news to the public.
What are the responsibilities of a journalist to the public discourse? 
They are meant to collect, write, or distribute news or even other current info to them and that is their responsibility. 
So is a journalist for the national enquirer the same as a journalist for the BBC? 
Well it would be more based on personal stories and the journalist's abilities in journalism.
Shouldn't a journalist have a responsibility to provided objective news instead of opinionated observations? 
Well they can work with general issues or specialize in certain issues, so they could provide objective news as well if they so choose.