Blue sky funding is essential and more usually than not government funded. Think of all the things we would not have if we had to depend on private/corporate funding alone, decisions made purely with profit in mind. You can't think of one, let me help you with a couple. Graphene, discovered under blue sky funding and the higgs boson. Both of which will prove essential in humanity's drive for the stars.
Not everything is about humanity. If we're only limiting our scope of scientific research to ourselves, we're excluding a whole variety of possibilities that are out there. Although science for the sake of humanity is important, it is also equally important to expand our interests outside of ourselves. We may discover marvelous things.
Funding for scientific research should be based purely on whether or not it directly benefits humanity. This is difficult to judge. There are also many research projects that do not seem to have a direct benefit, but later prove very useful. Research can provide unexpected benefits, which even scientists do not know at the outset.
We should spend our time and money more wisely so that we can make progress. We need to be more concerned about the important things in life like how to fix the global warming problem. If we don't act now it'll be to late and all of humanity will be at a loss.
If there is enough purpose in doing the scientific research, a private company will step up and fund it. Otherwise, if a person wants to do something just because they think it's a good thing to do, they either need to spend their own money or convince people to make private donations. It's not my job to fund a recreational activity for someone else.