-He didn't become strong. All he could do was to sacrifice his life for his comrades and let kakashi protect his friend.
-He never got to confess his feelings to Rin. She was in love with kakashi all the time...yet she was the only person that cared for him deeply.
-He's changed kakashi, that's true, but the world has stayed the same. Ninja still respect rules and sometimes commit atrocious things to carry out their missions. The root is a good example of this.
-The moment Obito thought he would die, his last wish, his deepest desire has been entrusted to Kakashi. Just like in Konan's case where Naruto became her dream itself, so is with Obito: kakashi became his dream, his eye trough wich he could observe a better future. Yet kakashi failed, even though he was a lot more skilled than obito. Obito trusted kakshi more than anyone when he was dying, but even a powerful ninja like him didn't carry out his duty.
He, Obito, was still a young boy, who spoke big things because he had HOPE. Everyone in narutoverse had hope once, but because of particular reasons they all lost it slowly until they became hollow. When his last bit of hope was gone, all his world crumbled, and before he could start re-building his emotions and re-gaining hope, Madara kicked in and completely tore Obito's view of reality apart. Moon eye's plan is tempting to someone who's always been a total failure, who had to go trough so many let downs. At once he could achieve everything he always desired: power and peace of heart.
You're too fast to determine whether it's a pathetic twist for him, for you haven't yet seen the arguments madara used to convince him. He almos made Oonoki shit his pants, and Obito's just a brat, a lot weaker than the tsuchikage was then. Who knows what things did madara promise him once their plan is complete. A perfect world for Obito where everything's ok...
He was just a child, Aga. A small, weak child. And an adult took his innocence from him, by affecting him with his darkness. I don't say it was Rin's death alone that produced those changes, but a whole chain of events that destroyed his life. Who should he blame? The rock ninjas? No. They were at war and they were just executing orders. The kages? Probably, but even them were pulled in that situation by hundreds of years of hatred. Then who? Kakashi? No...having revenge on one person is not going to make him feel any better, there would be only emptiness. A senseless emptiness left. THen what is the origin of all sufference? This world! Reality! It's its fault for stepping forwards and cruelly taking away things ppl care for! So I'll stop reality itself and everything: the pain, the hatred, the sufference, unfulfilled dreams, all will stop forever! He thought. Or madara told him that. He wants to eliminate the problem at its roots. And not just because he lost a girl, but because everything in the world is destined to fail, according to him, so what's the sense either way?
Let the timeline stay out of this. The only problem with obito is that he seemed too old when fighting minato. The years of academy don't have anything to do with him turning into Tobi.
ANd cool it. Don't you think you're gettin gway too depressed just because one thig in the manga didn't go as you wanted it to go? Maybe kishi hasn't shown us eveything he keeps in store for us? What about the huge revealtions aboyt the progenitor? Huh? Maybe they tie with Obito's past and explain what that little boy might have discovered that made him so twisted?
You say that Obito's motives were stupid, but you don't know anything that obito experienced in that 1 year. It takes a huge amount of things to change a person like that. Don't underestimate madara's manipulative skills!
Taking back the compliments for being a badass manipulator doesen't have anyhing to do with Tobi's identity! Whatever his reasons were, he is good at manipulating and disguising himself as other people. It just seems as if you're saying: "Oh, Obito's got a lame motive to be a villain, so I he's not a great manipulator anymore"...