not famous, praised, or admired, although deserving to be
I suspect the parent knows the meaning, but considers it wrong as applied to Ulam.
I wish the parent had taken the time and effort to actually make his point, instead of leaving an easily misunderstood, single-word non-comment in the hope of some easy fake internet points. This is how forums degrade.
Perhaps in an effort to increase the comment quality of HN, we should all pitch in some engineering time pro-bono to Reddit. Before you strike me down, think about it.