From New Scientist:

Billionaire internet investor Yuri Milner says he launched his $3 million science prizes to create heroes for the next generation

What is the goal of the new prizes?
Scientists are under-represented as heroes in our society. We intend to change that. This is not an objective in itself; it will in turn encourage younger people to go into science and also help to increase funding. The more attention you attract to science, the better off everybody will be.

Why do you think famous scientists are key to inspiring the next generation?
To inspire young people to go into science you need to show them the heroes of the present. People look at Usain Bolt and they go into running. You need role models to attract young talent. That is not emphasised in science. How many scientists are household names?

You launched physics prizes last year. Why did you create life sciences prizes as well?
Fundamental physics is at the forefront of answering big questions; I don’t think there is any bigger question than the universe. The next set of big questions is about life – evolution, disease, genetics, longevity and so on. So the life sciences are a natural second step.

How did you decide on $3 million?
There is no magic in this number, but it emphasises the importance of these people in society: not only Wall Street traders should be making millions. That said, I don’t think scientists are inspired by money. It’s not so much about the $3 million – though that’s not going to hurt. It is about showcasing the scientists. Millions of lives are saved every year by what these people are discovering, yet nobody knows who they are.

As much as I tend to scoff at “throw money at it” solutions to cultural problems, I believe this idea might have some merit.

While (ideologically, at least) scientific prestige is based on making contributions of scientific value, wider cultural prestige in our society is tied, at least in part, to personal wealth. This may redress the imbalance a bit. It’s true that there are already a number of wealthy scientists, doctors, inventors, etc., but they’re still uncommon enough to be considered somewhat anomalous.

Imagine a leisure class of scientists* with enough money to fund their own research, beyond boundary conditions of profitability created by someone else.

*you don’t have to imagine it, actually — for a long time, science was the hobby of the noblesse. The Royal Society of London was basically a social club for rich people who liked to do science for fun.