I agree that positive-thinking is for the best, but telling people that your life is going to be filled with lots of people who love and respect you is just disingenuous and naive. It's nothing but New Age nonsense. Stuff that wants to pretend like psychic powers exist, as if 'positive thinking' is somehow going to move the whole universe for you (as the quote you provided even states).
That is an ideology driven by New Age culture, preached by the Prophets of Capitalism, and followed by all the lost people who have been led astray by the cult of consumerism. A message catered to all the privileged people in the world who already have a life full of loving people who respect them, but are just too blind to see them. They just want to sell you on crap like 'healing crystals' and all the other nonsense that requires psychic powers to utilize, or just tons and tons of self-help books. It's all one big scam. They're just taking advantage of the weak, like most try to do.
And once people realize that, once they think positively and still have no friends, no family, and etc. That's when they realize they've been taken advantage of yet again and are delivered even more hopelessly into despair. These sort of lies are also the kinds of things that lead people to suicide. Making people, at their most vulnerable times, feel like nothing more than just easy money, and not just that, but putting blame, for everything, solely on them. Telling them it's the way they think and act which causes all of their problems. 'It isn't the world, it's you!'
... Oh, if it were only that easy.
Call me bitter if you'd like, but the reality of this is very clear. A positive self-image is very good for you, but it's not going to magically change everything in the world. It's not going to change people. It's not going to "move the entire universe" at all, it won't even budge. It's not going to lure a lot of friends to you, it's not going to heal your sickness, and it's not going to change anything but your own self-image. If you want the universe to move, it is as it always has been, you must move it yourself. The only truth to this is that you can't begin to know how to start moving the universe until you learn to move yourself, which requires a positive self-image as well as some determination.
Not to mention, as 0doc explained, that you can't just expect people who don't have any supportive people in their lives to just get up and do this. It doesn't just happen overnight. They first have to seek out people who will support them and accept them for who they are, whether that is people online, a therapist, family members, or even just a stranger they met on the bus, then, only after that, can they learn to accept themselves.