Because they are the result of "Collaborating with 13 designers around the world" -- so, assuming they're competent in their jobs (which they look to be, judging from their individual profiles you get when you click on a palette), would be better than what some random dev will come up with.

Note that nobody says those are worth using "above others" (much less "above all others").

Just that those are well put together palette suggestions by professional designers.

(And I'm sure they used color theory in their selections, judging from 2-3 palettes I've examined).