Yes, i agree. If i remember correctly, from our last discussion on PLN, we had came to an understanding the ConceptNodes are sets and as such SatisfyingSetLink as the second argument is appropriate. 

(InheritanceLink (stv 1.0 1.0)
    (ConceptNode "scientist")
    (SatisfyingSetLink 
             (VariableNode  "$x")
             (AndLink  .....)))