How much time is too much time invested?

So here's a pretty incredible story about a man in Peru who, more than thirty years ago, had a vision for improving the future of his small town:

http://dowser.org/money-does-grow-on-trees-in-one-peruvian-town/

He basically foresaw that forestry could help take them out of poverty, and also provide the fuel necessary to improve their lifestyle. Even though he knew it would take years- 20 years for the trees to grow to the point where they could be used- and others thought he was crazy, he pursued his project. Now, thanks to his project, education, healthcare, and the everyday lives of the people have all improved.

What's shocking to me about this story is that this is a social project that had to be kept alive for such a long period of time before it became beneficial, and that Don Alejandro Quispe Chilón knew the years he would have to invest, and still pushed forward. I think that a lot of the mentality today, both in general and regarding social innovations, is to get and outcome as soon as possible. But what about cases like this one in which as soon as possible is still just not soon? I'm inclined to say that in these cases, most people would give up, or look for other projects to pursue. Because if people can spend their time finding outcomes and benefits for the immediate future, why would they instead spend their time investing in the long-term future?

Of course this is a generalization, and maybe this isn't even a fair assessment of today's mentality. It's clear that social projects take years to go from conception to fruition. Yet it seems to me that in the other cases we've seen for this class, the time frame is dependent more on the perfection of an invention or the creation of a sustainable business. This means that there are may variables that contribute to the overall time frame in which a project can be completed, and therefore there is not a set future date when benefits can start to be reaped. So when there is a 20-year future date, would most people still be willing to invest? And nowadays, do we really have that much time to invest?