Capitalism doesn't work like this. Resources are allocated via crazy, unfair market actions. 300 years ago, most of Europe resembled what we would call the Third World now. Epidemics, warfare, starvation, etc. The big driving force that changed Europe wasn't the generosity of kings, but the base-level trading and investing among the poor and emerging middle classes.
There were a lot of resources being misspent back in those days. Anyone remember a particular Dutch fascination with tulips? Money was spent on doomed voyages of exploration, fake medicines, flower-based stock bubbles, and any number of other "follies" that in hindsight could have been avoided.
But among all the mispenditure of resources over hundreds of years, hundreds of millions of people were lifted out of poverty. We went from an average lifespan of 40 years to over 80. We live in an actual age of marvels.
In our modern world, we have people building entire companies and fortunes around what are the silliest things. We have even more people copying the first successes and failing. In amongst that, there are the smaller numbers of people building companies that will laterally help those who's lives need improving.
If we lived in a society where our resources could be marshaled enmasse towards one goal or another, it wouldn't be the world we have now.
Telling entrepreneurs that one class of businesses is more socially correct than others isn't how the world works. People will find opportunities in many ways, and those will benefit the people in need. The poor will find edges in the market to improve their own lives. What might seem worthless to you might be valuable to someone else.
So if you have an idea for Bitly 4.0, do it. If you want to build cheap rockets to space, do it. If you want to build a social networking app that uses cheap cell phones to let goat herders in sub-Saharan Africa poke each other over hundreds of miles, do it. You never know how or when your product will be used, or who it will help.