It is true that the world cannot only see positive. Worry will always exist. Anything and everything you ask for in life has a possibility to not come true. And as long as that possibility exist, worry will exist. Especially if your impatient. Impatience causes more worrying. But as far as objects, toys (cars, houses, etc.) not everybody wants the same thing, and there's plenty to go around.
And as far as the world not being able to handle that much positivity, look at the world now. If there's a big positive negative scale, we as a planet are leaning heavily on the negative side and the planet hasn't spontaneously combusted. So why could't we exist leaning heavily on the positive side. With this way of thinking an living we can all have the toys we want, and live the lives we want. So lets tip the scale in a positive direction! We've been way to negative, for way to long.