I don't think anyone questions the usefulness of it, just how much is coming out. Maybe I'm missing something. I took my throttle body and intake apart at 187,000 miles and there was a a little gummy varnish at the very end near #4 from the crankcase ventilation but not so much that I thought I needed to install an oil separator. The back of my TB throat plate gets a little sticky after a few years, but not excessive. Now I do rotate PCVs every oil change, one on deck sitting in solvent while the other is in the valve cover, which may have something to do with it.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
“Anyone who believes in indefinite growth in anything physical, on a physically finite planet, is either mad or an economist.” -- Kenneth E. Boulding