I don't hate oneworld per se: overall, the alliance has some strong members that I wouldn't mind flying again (CX, MA [RIP] and BA come into mind for me). What I don't like is an airline joining an alliance so that its role would be merely to feed the strong neighboring airline, rather than be given an incentive to induce organic growth.

The PR-CX relationship for me is contentious in this way: I'm afraid that if PR joins oneworld, CX will reap all the benefits of such a relationship to the detriment of PR (that is, if PR doesn't try to eat market share away from CX first when major expansion kicks in). If they've tried to do it before back when PR was in bankruptcy, what's there to say that they won't try it again?