As for 'needing' PhDs, I'm not sure. Having some can be convenient, yes, but in many cases not necessary. In some fields the only way to get caught up (i.e. no corporation will train you directly) may be with academic foundations but is a PhD necessary or just some relevant graduate work?
As an example N=1 to show a PhD is not needed always, Jeff Jonas formerly held the title of IBM Chief Scientist where he did some state of the art work in entity resolution. He didn't even finish high school.
Further, since your original position was strongly that academia is useless, it is your onus to back up the implication that PhDs are not (generally) needed/useful, and using "well hmm, not sure if absolutely necessary" logic is fallacious and clouds the issue.