I appreciate your points, but both approaches are legitimate portraiture. I’m a big fan of White, and Liebowitz does some excellent work, although she trends far more towards the Maplethorpe/decadent genre than I am comfortable with. The Whoopie pictures are grotesque, but memorable.
There are several problems with Art from around 1950 on. It’s based as much on being distinctive as it is being good.
White worked with available lighting and figures and happenings of actual historical significance. She was an early master in photographic composition, and put herself in significant danger to get her shots.
Liebowitz is a good photographer, but her subjects tend to be the glitterati of the moment, although she has done some notable figures. Her work is more baroque and decorative than White’s. White always kept a photo-journalistic tempo to her photos. Liebowitz seems more like a painter making a composition. It’s more formal and staged, but the lighting is perfect, and there are decorative touches all over the place.
Leibowitz was a studio portraitist fulfilling commercial assignments, a whole different line of work technically. Studio portraiture requires sets, lighting, a staff of assistants, advance and follow-up work, extensive interaction with agents, clients and publication photo editors, remote location and prop rentals, continuous equipment and software upgrades and archiving systems. Her approach was closer to producing a feature-length movie than snapping a Brownie. A business on her scale would require substantial overhead and cash flow, even if she hadn't gone overboard.