Where did TOS ever present the idea that "Vulcans aspired to rationality in principle but frequently fell short of that ideal" as a race? You're making that up. Name a single TOS full-Vulcan for whom that is true?
Well, there was Sarek who didn't speak to his son for eighteen years because he disapproved of his career choice. And who concealed a serious heart condition from his wife.
And T'Pau, who insisted, for the sake of tradition, that Kirk fight Spock to death--even when it was very obvious that Kirk had no idea what he was getting into. (I mean, would it have killed her to make sure Kirk knew he was risking his life before he agreed to an obscure Vulcan ritual?)
And T'Pring and Stonn, who . . . well, we remember.
Basically,
every full Vulcan who appeared on TOS, with the possible of exception of Surak in "The Savage Curtain."
And Surak is an interesting case. He's definitely portrayed in a very positive manner, but he does end up getting himself killed, leaving Kirk to win the conflict between good and evil. (Or so I recall; I haven't seen that episode in years.)
If the message of
Star Trek was that we should be more like the Vulcans, then Surak would have shown Kirk and Yarnek the wisdom of his ways at the end of the story.