"Professional journalism" was pronounced dead when The Fabled NYT published fables and plagarized tales as a matter of routine.
That means "professional journalism" is a rather short-lived phenomena, considering that Bill Pulitzer invented it around the turn of the last century as a circulation gimmick. Back when Pulitzer and Hearst were battling for circulation in New York and other cities, each tried gimmicks to beat the other. That's when comics were introduced to newspapers, and when the half-tone printing process was put to increased use to print photographs on newspapers front pages.
Pulitzer decided that it might be a good circulation gimmick to flank Hearst's highly sensational and biased writing style with its opposite, calm and unbiased reporting. Pulitzer almost single-handedly created the entire idea of the reporter as "journalist". And it was done for no other significant reason than to sell more papers than Hearst, even though the introduction of the gimmick was surrounded by high-sounding rhetoric.