The thing is that Oda never made it seems like marines had any intent to rebel to begin with.
I always assumed good-hearted marines worked with the WG because they bought the propaganda, and the WG was still a better alternative than a chaotic world.
Like Ohara destruction, the propaganda was that the scholars broke the law were doing dangerous research that could awaken ancient weapons.
But genocide for the sake of entertainement? I don't know how you could twist that.
I'm assuming the Marines don't know about it and only certain ones do at most, the most trusted ones.
We saw Saturn willingly killing a Marine for making eye contact with him, for being "too low rank to witness him" and in China, there was that rumour at least, that this Emperor in the "Forbidden City" would have you executed immediately if you were to look inside of it and see them? So I thought Oda was referencing that too for example.
Saturn referred to all humans as insects pretty much too, expendable trash basically. Doberman was horrified by that too evidently.
We've got good natured Marines defecting or being kicked out and joining Sword instead, going rogue like Koby and Drake for example ofc.
Maybe Kuzan found out about stuff like this with the WG and thats why he defected so brazenly too?
I've always felt a lot of Marines including some Admirals, especially Akainu and Kuzan were fed massive propaganda, brainwashed from a young age to be completely obedient, passionate, non-questioning dogs of the WG, the ultimate super soldiers.
Oda has been using Smoker and Tashigi to show the good in the Marines, that they're innocents on the Marines' side too, like with Koby too ofc. Hell, as someone said brilliantly recently, Fujitora is playing the role Smoker was meant to, Smoker is the one who fell foul of multiple Warlords now and should be the one pushing for the abolishment of Warlords more than anybody else by far. It would have been dope if Smoker had gotten close with Fujitora and thus they decided to abolish the Warlords together then at least. Given the setup from Punk Hazard to Dressrosa too, this would have made most sense too.
Fucking crazy we waited YEARS to see Smoker and Tashigi going to Vegapunk too, only for Tashigi to appear twice briefly as cameos during Vegapunks arc after all these YEARS and Smoker still NOWHERE to be seen and no single of mention of him and Fujitora like they've been forgotten or silently written out of the story!
But yeah, maybe this shocking incident is not only the exposure of Imus existence and the "not empty throne" to the entire world, but Saturns true form/nature, Gods Valley and Lulusia and thus what happened to them and why they disappeared, the real reasons Ohara was destroyed and all the lies/facades of the WG, the proganda AND also this absolutely beyond words evil atrocities of the WG on Gods Valley as implied there was going on since it was mentioned before too. One Piece version of Roman Coliseums and dogfighting/cockfighting.