Of course journalists have opinions just like everyone else, and of course they don't have to conceal their opinions. However, like you wrote, journalism is not about one's opinions but about describing reality. A good journalist does that in her or his own voice, but knows how not to cross the line between writing from a personal point of view to writing about her/him self
Reality is subjective to a large degree. In people's minds, that is. Of course we all know that there is an objective reality, but we can never escape our own heads, so reality shows itself differently to different people.
great points! thx for your feedback and thx for reading :)