To me, the lack of interlining on separate PNRs would be a HUGE inconvenience and definitely affect my choice of carrier.
I'm almost always travelling on a cobbled together collection of sectors across different bookings and while I avoid checked luggage, sometimes something has to go in the hold. FWIW a few months ago QF had no issues through checking bags onto MH (different booking and different class of travel) but it took the check-in agent quite some time to accomplish.
Anyway, if this feature of Oneworld goes away, they can expect passengers to go away as well
