Keeping to the comparison with Russia, I think the data bears out my point.
https://en.wikipedia.org/wiki/Demography_of_the_United_State...
That's a very different story than the Russia link you provided, which, as I suspected, says that the country is mostly a) ethnically Russian and b) the rest are minorities the Russians have been dealing with for most of their history. I've even seen suggestions that the "White" category is perhaps too coarse, with observable cultural and political differences between whites of English descent and whites of German descent.
There's another pertinent datapoint, which is that Russia has a very low TFR and is experiencing a population decline and is pursuing policies to reverse that, as it is seen as a major problem. The US, on the other hand, continues to grow, largely because of immigration; policies to increase the number of children are superfluous.
That said, as I mentioned earlier, I think that's just a factor. Every country is special and has to be considered on its own terms. Is geographic size a factor? Probably. Is population size a factor? Probably. Is population diversity a factor? Probably. Is some remnant of the mythological self-reliance of American frontierism a factor? Probably. Is the rivalry with the USSR a factor? Probably.
Moreover, while I personally would like at a minimum a year of paid parental leave, the idea that parental leave represents Forward Progress and any country that doesn't have it is backward and deserves to be shamed is rather disturbing. Instead of trying to shame America to conform to somebody elses' norms, we should probably work instead on convincing them that it's a worthwhile and workable idea, and that the potential tradeoffs are worth making.