It sounds like your experience is exclusively with open-science DoE user facility machines. What you're saying is true for the bulk of working scientists, not

It sounds like your experience is exclusively with open-science DoE user facility machines. What you're saying is true for the bulk of working scientists, not enough of whom are given funding to make efficient code -- just to make working code. However, even on those systems there is some good competition for the Gordon Bell prize each year. Meanwhile, Defense and closed-science systems of similar scale continue to be used at very good efficiency on problems that are strictly non-feasible on smaller clusters. The leadership-class systems are prestigious, and that prestige helps drive needed technological advances, even if the places that need them aren't in the university system.