Lets approach this a bit differently - Is there something inherit within a segment of our population that makes them more meritable and "better scientists"? The answer is either:
- Yes, a subset of our population is superior and awards like Nobel Prize should be dominated by them
- No, everyone is generally of equal skill and merit (or potential), and the Nobel Prize should roughly, on average, be awarded to people that look like the population.
Then, considering your answer above, how does that match to reality? What accounts for this mismatch? Why are fields (and awards like this) underrepresenting our populations?
If you want "the best science" and to be continuously improving the field, don't you want to make sure you're not shutting the door on whole demographics? To say "focus exclusively on merit" seems to suggest that you think that merit favors one demographic.