Nothing, but they won't. They are too risk adverse. Funding science, and even the things that came before science, is a traditional function of government, and unlike many such, one that ultimately benefits everyone. Government needs to fund the leading edge stuff, where no private business will go. Once the basics are known, then private enterprise does a great job of applying those basics as needed and appropriate. The difference is one between basic and applied research.
In the 50s the military funded a lot of both, although not in general the most basic stuff, but rather stuff that might conceivably have some military application, with the emphasis on *might*, or which would serve to train the next generation of scientists, most of whom would work in the applied area rather than the basic research. And it paid off handsomely.
These days the government actively discourages applied research, by deeming the funds that would pay for it, "excess profits" or the result of monopoly power (you could take a look at Bell Labs, probably the finest corporate applied research organization the world has ever known, if it still existed as something other than the Alcatel/Lucent advanced developement organization It is today. . (And Not the rodent control folks either. :)) The old Bell Labs was killed by the United States Government.
I sure would like to meet Mr. Gum’t. He is such a generous guy.