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 Pickup - Imelda
'08 Tacoma TRD - Donna