Originally Posted by Emissary of Justice
You're thinking small, simply looking at the motivation for being bad instead of the the actual end game.
Pain's plan: Drop Juubi-level Tailed Beast Bombs on any country that steps out of line.
Sasuke's plan: Wipe out all of Konoha.
Obito: Force the universe into peace through genjutsu.
With what Obito wants, he's hardly an emotional sap. Did Rin dying drive him back to Madara? Yes, because like Nagato, it made him realize his idealistic view doesn't work in this world. Outside of his bitch fit the day Naruto was born, he only employed methods that harmed non-Jinks when the Kages wouldn't peacefully accept his proposal. That's hardly the "everyone needs to suffer because I'm unhappy" approach from the other two.
The confusing part of this is he obviously is. You pose an Obito in a story like this. After Madara helped Obito's crushed body into his cave, hooked him up with life, Harashirma DNA, Zetsu suits, he would simply sleep, Madara. During that time Obito was growing up on his own like he was in college, and from time to time he'd go to places like the Uchihia hideouts, and then he discovered ON HIS OWN this great plan for Tsukiyomi and either Madara's cool with it, or its his own secret plan that Madara dosen't know. Either that or PRIOR to getting crushed, JUST after awakinging ONE Tomoe (not even up to the full 3), he had such knowledge back then during his academy days.
Tsukyomi for the world is Madara's plan, he wants zero opposition, and is an emotional mess because his arch enemy Harashirma's gone and he has no more goals. Anything else drawn from they're 'relationship', or Obito's wants, is a reach, a stretch, a hope, a dream, fanfiction. Thinkit, BOTH Madara, and Obito from Harashirma's DNA, don't eat, don't drink, don't need sex, to shit, piss, or take a shower, no wonder Madara's bored. Obito simply seems like when he's in his own character that he never grew up, like I stated a hybrid Naruto/Sasuke when they were much, much, younger, before Shippuuden.