If you had of kept reading you would have seen them say that it doesn't matter if they were trained in higher education or in the newsroom as long as they were trained.
And then if you read a little more you'd see that this blogger hadn't structured it very well and seemingly contradicts one para with the following one:
A bachelor’s degree in journalism, media studies, mass communication, or some similarly named program along with at least a few years under the tutelage of editors is the best preparation for calling oneself a journalist.
Suggesting that one needs a BA along with years of tutelage.
In any case I'd like to retitle the piece "No true journalist". She sounds like a cabinet maker bemoaning the Ikea-isation of furniture.
Best case not only case. Having the formal education then adding a few years experience. The alternative case she listed was just the experience in the newsroom.
Best case to prepare to call oneself a journalist sounds like it would be essential to actually doing it, rather than being preferential in preparing to do it. But yeah.