Sometimes RWBY annoys me
Ozpin was a tragedy. The terrifyingly young headmaster of arguably the most famous of the Huntsman academies, shoved into the place he was in solely because of Ozma.
People conflate them, but they're not actually the same person. Ozpin hates himself, even after death... but there's no real evidence that Ozma does.
He's horrified that he's taking over Oscar because that was never meant to happen, he hoped to be the last just as much as previous Ozcarnations did... maybe even more, considering where he was and the protectiveness he feels for his students. Oscar, given a few years, could so easily be a Beacon student, after all.
He ran, he locked himself away and yet that still wasn't enough to stop the merge. OZPIN did not ask Jinn the question shown and we don't even know just when he was given the particular information that that even happened. Should he have shared it? Yes, maybe. But then again, he'd only known team RWBY and what's left of team JNPR for about a year when they all jumped him for not telling them and we do have canon proof that when he trusts people [Lionheart and Ironwood] they can and do betray that trust for their own reasons.
What's worst? He's fighting a war he no more signed up for than Oscar did, yet everybody seems very set on blaming him, as the last Ozcarnation, for the sins of them all.
Ozpin might be the voice, but that's merely because he was the last. EVERY incarnation of Ozma is a tragedy, it's one of the shittiest reincarnation methods in fiction. 'You'll never be alone', no, but the process gives the new host exactly no choice in the matter.
Basically... Oscar is a victim, but so was Oz. And it's quite likely he might not even have been in double digits when it happened.