I agree up to a point (having one myself) — at pretty much every job I’ve had in the industry, some of my co-workers have come from other majors, and for the most part they’ve done fine. In fact, for those who do major in journalism, I’d highly recommend a second major in a field of interest (mine was political science).
However, there is more to journalism than basic writing skills, and publications need to keep an eye on those without degrees when it comes to these areas — things like AP style, proper communications with sources, ethics, law, care with facts, conflicts of interest, etc.
Basically, a journalism degree isn’t necessary for a good career in the field, but employers should (and do) see it as a bonus.