My pleasure @al-hekima-madara-blog , your fics have so much life and charcters have the depth that we didn't get to see before . It just feels so authentic , while doing justice to the time period it was set in.
Additionally, someone with the amount of guilt he had would never want anyone else to suffer like he himself did. I guess that's why he thought that "the eye of the moon plan" would be perfect, he wanted to execute it on any price and condition because he had The Clear Vision, the one he developed in years isolation by seeing the world in a completely detached manner , emotions not clouding his observation , analysis and judgement. He must have spent years thinking of every possible solution to the problem but got to the conclusion that "eye of the moon plan " is the last solution to solve it at it's root .He must have felt like a saviour cause he read the stone tablet, accepting everyone else is ignorant , that's why it's his responsibility to save the people of the world from what he has already suffered through.
Reminde me of the saying
(Just like if you get into accident caused as you didn't fasten your seat belt , after that accident you make sure all your family and friends in the car does it before the car starts.)
Since his pain was greater the scale of people he considered became global .
Unfortunately we never had flashback on Madara's youth. So understanding him is always like playing the detective and putting dots together. But there is a brief moment where we have an idea of his mindset during the warring state era. It's the long Obito's monologue just after Neji's death. It's the only moment where Madara recognizes himself. And what I see is that solitude is what really hurt him the most and definitely makes him lose his faith on any of his principles. In comparison the old Madara here is beyond pain, age has distant him from that. Often he's quite bored about grandiose optimistic speech from other characters, people he knew are gone, nothing to believe in except stopping this reality, this world doesn't matter anymore to him. So read Obito carefully and replace it with Madara, it gives a new light to what his life could have been.
I want to put this also in parallel with Onoki's memory. His sensei was giving him a personal lesson, but that speech is intentionally a parallel with Madara's life. And we know that at this precise moment he had lost hope in Konoha, and was losing the trust of his own clan. In other word, even if he was one of the most powerful shinobi of his time, he's absolutely isolated and unable to defend his principle or Izuna's will.
And of course there is the nail on the coffin when he read the tablets. He found himself in a desperate situation and the infinite plan comes like a miraculous answer to his pain. Then, he puts all his energy into achieving it.