I think it's two things causing us not to dream anymore : judgement and fear. People have become too afraid to be judged, to pursue their dreams. Me personally, i'd like to build a spacecraft and an iron man suit. Most of you will tell me i wont succeed. Do I care? No. Thats why i started studying physics ; im pursuing my dreams! Many of my friends are just happy when they eat, live and die. The other thing component is fear. People rather stay in their comfortable homes than go out. They dont go out to bars meeting strangers. I think " may you live in interesting times" is a chinese curse . Concluding, I think people are too scared of either whats to come, and of being judged. Take away these elements, and people will dream again. One thing I think may catalyze this is a common goal. People on the moon, mars or beyond? Everyone will share a sense of connectedness, which will be very benefiting to mankind as a whole.
I agree with you that these are at the root of the issue, along with a few others (such as a lack of community. But, that might be from judgement as well). And the world needs more people like you then. Those who aren't afraid to go after their dreams, even after they've been told countless times that they'll fail. Can I get a ride in the Iron Man suit once you've built it?
I actually excel when people tell me it cant be done. Ordinarily, i quite often say 'cant be done', but when people tell me, ill keep on going until it can be done. Why? I hate people telling me what I can and cant do. And sure you can, you can even help me test it! I just need to learn autocad, lots of physics , chemistry and biology, buy some 3D printers and we're good to go!