Does Ichinen Sanzen include "wishful thinking"? Does Ichinen Sanzen include "wishful thinking," or am i getting it wrong?

Also, does Theravada buddhism include "wishful thinking?"

This is the text I read that made me have this question:

http://www.sokahumanism.com/nichiren-buddhism/Practical_Meaning_of_Ichinen_Sanzen.html
Ichinen Sanzen isn't really wishful thinking, because it's not just hoping for a situation to get better— it's actually working for a situation to become better.
Wishful thinking implies that the subject expects the situation to change, whereas Ichinen Sanzen (3000 realms) implies that your own outlook  needs to change. This means not viewing oneself as victim of one's environment and basically that the concept of goodness and badness only exist in out head.
Here is a quote that Nichiren (a buddhist monk who propagated the 3000 realms) wrote in one of his letters to a follower that I think gives the gist of the idea of Ichinen Sanzen:

&quot;The Vimalakīrti Sutra states that, when one seeks the Buddhas’ emancipation in the minds of ordinary beings, one finds that ordinary beings are the entities of enlightenment, and that the sufferings of birth and death are nirvana. It also states that, if the minds of living beings are impure, their land is also impure, but if their minds are pure, so is their land. There are not two lands, pure or impure in themselves. The difference lies solely in the good or evil of our minds.
It is the same with a Buddha and an ordinary being. When deluded, one is called an ordinary being, but when enlightened, one is called a Buddha. This is similar to a tarnished mirror that will shine like a jewel when polished. A mind now clouded by the illusions of the innate darkness of life is like a tarnished mirror, but when polished, it is sure to become like a clear mirror, reflecting the essential nature of phenomena and the true aspect of reality&quot; (The Writings of Nichiren Daishonin   vol. I 4).

You'll notice that he is referring to perception of events and not just wishing problems away. That's the difference between The 3000 Realms and wishful thinking.
If you want a more technical definition of Ichinen Sanzen where I break down each part and say how it works, I'm happy to do so. Just add a comment to my answer asking me.
Anyhow, I hope this helped!
Edit: I'm not really sure about the specifics of Theravada Buddhism, but I know that both wishful thinking and Ichinen Sanzen aren't part of Theravada Buddhism.
Wishful thinking isn't a real practice in Buddhism regardless of the sect, and The 3000 Realms was developed by T'ien-T'ai, a Chinese, Mahayana monk; so, it's not part of Theravada Buddhism either.