I can't speak for the OP, but I can give you my example. I live in Australia and have a QF account. It's easy to earn QF points through credit cards, shopping, etc. I travel on QR a bit (enough to be Gold) and OneWorld being very limited in terms of member airlines cooperating, if I want any benefits I really need to be a QRPC member. I'd prefer to stick to just one of them, but (a) I can't earn QR Avios in Australia with non-flying activities (and you barely earn Avios when flying QF), and (b) QF membership is useless when flying QR (e.g. you can't use QF points to upgrade)