It's one step towards gender equality; if you use quotas to award different population groups equally, it will on the one hand normalize them for everyone else, and may inspire others to try on the other hand.
If the top of whatever Nobel prizes are handed out for remains white men, nobody that doesn't fit that category will feel like they have a chance.
Anyway, it's one strategy; the other, and IMO more important one, is to give everybody equal access to education and the sciences. This is a governmental issue, who should be paying for everyone's education, transport to said education, and if need be, housing near said education. And of course strict anti-discrimination and anti-elitism laws. Breaking up concepts of 'class' should also be a thing, since right now, working class people will be less inclined to go to university for example.
I've been lucky in that regard; grew up 'working class', but thanks to the at the time government policies of giving out stipends for education I got college educated and a career in software development, moving up to middle class. It's a great example of social mobility, and I think everyone should have that opportunity.
But after my education, the government pulled up the ladder behind me. First by changing the scholarship rules so that after a certain age you are no longer entitled, making it harder for people to go from college to university for example. Then they changed it so it's 100% a loan, which on the one hand makes people less inclined to start a higher level education, and on the other it starts their career with tens of thousands of debt, making it harder to e.g. buy a house and start a family alongside their career.
I mean there's voices going up to undo those changes now, but it's been years under this shitty system and damage has already been done.
It's stupid as well, because it's a relatively small cost at great benefit - it doesn't make financial sense. Say an education costs the government 50.000 per person. That is repaid in income taxes alone within 3-5 years.
edit: well this comment meandered a bit.