I respectfully submit that this "problem" is caused by inconsistent application of the "standards" (used very loosely, as it applies here) for authoring Blu-ray discs and their associated interfaces. I wish the studios and production houses would spend less effort trying to come up with new/flashy/fancy interfaces and such - and spend more effort on CONTENT and a consistent and universal menu/access system.
But, I guess that may be just too much to ask for!
However, until such time, there will always be problems with BD use. More problems with some players, less with others. Pointing fingers at Oppo, or any player manufacturer is not productive. Perhaps, the frustration and disappointment would be better directed at the real cause of the problem.