As far as the BF statement it’s ridiculous. Of course they can beat him he is dead. I hate comparisons like that.
However I will say I doubt any player today could preform like Bob did with the attention and Cold War political pressure of USA vs USSR he was under.
it's not so much how good he is to me but that he plays where we can watch and see. he will also play non ranked players and you can tell him to play people you want him to play. he's the peoples champ so to say
This.
Nakamura plays all kinds of players, even the weak and lousy (comparatively) FMs and NMs. The same cannot be said about the other top players, especially Carlsen.
By playing with "lousy" players, he exposes himself to costly defeats which may also hurt his reputation, but still he manages to keep his rating high. He puts his neck on the line. That's one of the reasons why he is popular, and NOT just with Americans here....
His problem with Carlsen is mainly psychological. He has no issues bumping off other very strong GMs, but with Carlsen, I guess he plays a few hundred points lower than his true ability...
Play the board, not the person.